diff --git a/source/compiler/memfile.c b/source/compiler/memfile.c
index e67884f..4b57615 100644
--- a/source/compiler/memfile.c
+++ b/source/compiler/memfile.c
@@ -76,7 +76,7 @@ size_t memfile_read(memfile_t *mf, void *buffer, size_t maxsize)
 
 	memcpy(buffer, mf->base + mf->offs, maxsize);
 
-	mf->offs += maxsize;
+	mf->offs += (long)maxsize;
 
 	return maxsize;
 }
@@ -98,7 +98,7 @@ int memfile_write(memfile_t *mf, const void *buffer, size_t size)
 		mf->size = newsize;
 	}
 	memcpy(mf->base + mf->offs, buffer, size);
-	mf->offs += size;
+	mf->offs += (long)size;
 
 	if (mf->offs > mf->usedoffs)
 	{
diff --git a/source/compiler/sc1.c b/source/compiler/sc1.c
index 97f1fd6..d3fa3fd 100644
--- a/source/compiler/sc1.c
+++ b/source/compiler/sc1.c
@@ -1043,7 +1043,7 @@ static void parseoptions(int argc,char **argv,char *oname,char *ename,char *pnam
 #endif
       case 'i':
         strlcpy(str,option_value(ptr),sizeof str);  /* set name of include directory */
-        i=strlen(str);
+        i=(int)strlen(str);
         if (i>0) {
           if (str[i-1]!=DIRSEP_CHAR) {
             str[i]=DIRSEP_CHAR;
@@ -1316,7 +1316,7 @@ static void setconfig(char *root)
       *(ptr+1)='\0';
       base=ptr;
       strcat(path,"include");
-      len=strlen(path);
+      len=(int)strlen(path);
       path[len]=DIRSEP_CHAR;
       path[len+1]='\0';
       /* see if it exists */
@@ -1329,7 +1329,7 @@ static void setconfig(char *root)
         if ((ptr=strrchr(path,DIRSEP_CHAR))!=NULL) {
           *(ptr+1)='\0';
           strcat(path,"include");
-          len=strlen(path);
+          len=(int)strlen(path);
           path[len]=DIRSEP_CHAR;
           path[len+1]='\0';
         } else {
@@ -4008,9 +4008,9 @@ static int find_xmltag(char *source,char *xmltag,char *xmlparam,char *xmlvalue,
   /* both NULL or both non-NULL */
   assert(xmlvalue!=NULL && xmlparam!=NULL || xmlvalue==NULL && xmlparam==NULL);
 
-  xmltag_len=strlen(xmltag);
-  xmlparam_len= (xmlparam!=NULL) ? strlen(xmlparam) : 0;
-  xmlvalue_len= (xmlvalue!=NULL) ? strlen(xmlvalue) : 0;
+  xmltag_len=(int)strlen(xmltag);
+  xmlparam_len= (xmlparam!=NULL) ? (int)strlen(xmlparam) : 0;
+  xmlvalue_len= (xmlvalue!=NULL) ? (int)strlen(xmlvalue) : 0;
   ptr=source;
   /* find an opening '<' */
   while ((ptr=strchr(ptr,'<'))!=NULL) {
@@ -5924,10 +5924,10 @@ static void dostate(void)
         listid=-1;
       } /* if */
       listindex=0;
-      length=strlen(name)+70; /* +70 for the fixed part "<transition ... />\n" */
+      length=(int)strlen(name)+70; /* +70 for the fixed part "<transition ... />\n" */
       /* see if there are any condition strings to attach */
       for (index=0; (str=get_autolist(index))!=NULL; index++)
-        length+=strlen(str);
+        length+=(int)strlen(str);
       if ((doc=(char*)malloc(length*sizeof(char)))!=NULL) {
         do {
           sprintf(doc,"<transition target=\"%s\"",name);
diff --git a/source/compiler/sc2.c b/source/compiler/sc2.c
index eac9ed2..a79d71e 100644
--- a/source/compiler/sc2.c
+++ b/source/compiler/sc2.c
@@ -377,7 +377,7 @@ static void readline(unsigned char *line)
           *ptr='\0';    /* erase '\n' (and any trailing whitespace) */
         } /* if */
       } /* if */
-      num-=strlen((char*)line);
+      num-=(int)strlen((char*)line);
       line+=strlen((char*)line);
     } /* if */
     fline+=1;
@@ -1385,7 +1385,7 @@ static int command(void)
   case tpUNDEF:
     if (!SKIPPING) {
       if (lex(&val,&str)==tSYMBOL) {
-        ret=delete_subst(str,strlen(str));
+        ret=delete_subst(str,(int)strlen(str));
         if (!ret) {
           /* also undefine normal constants */
           symbol *sym=findconst(str,NULL);
@@ -1632,7 +1632,7 @@ static int substpattern(unsigned char *line,size_t buffersize,char *pattern,char
         arg=*(e+1)-'0';
         assert(arg>=0 && arg<=9);
         if (args[arg]!=NULL)
-          len+=strlen((char*)args[arg]);
+          len+=(int)strlen((char*)args[arg]);
         else
           len+=2;     /* copy '%' plus digit */
         e++;          /* skip %, digit is skipped later */
@@ -2699,7 +2699,7 @@ SC_FUNC void delete_symbols(symbol *root,int level,int delete_labels,int delete_
 SC_FUNC uint32_t namehash(const char *name)
 {
   const unsigned char *ptr=(const unsigned char *)name;
-  int len=strlen(name);
+  int len=(int)strlen(name);
   if (len==0)
     return 0L;
   assert(len<256);
diff --git a/source/compiler/sc3.c b/source/compiler/sc3.c
index fa2f771..8294cd2 100644
--- a/source/compiler/sc3.c
+++ b/source/compiler/sc3.c
@@ -1310,7 +1310,7 @@ static int hier2(value *lval)
     if (sym!=NULL && sym->ident!=iFUNCTN && sym->ident!=iREFFUNC && (sym->usage & uDEFINE)==0)
       sym=NULL;                 /* symbol is not a function, it is in the table, but not "defined" */
     val= (sym!=NULL);
-    if (!val && find_subst(st,strlen(st))!=NULL)
+    if (!val && find_subst(st,(int)strlen(st))!=NULL)
       val=1;
     clear_value(lval);
     lval->ident=iCONSTEXPR;
diff --git a/source/compiler/sc6.c b/source/compiler/sc6.c
index df6b61a..c5e2b68 100644
--- a/source/compiler/sc6.c
+++ b/source/compiler/sc6.c
@@ -755,7 +755,7 @@ SC_FUNC int assemble(FILE *fout,FILE *fin)
         assert(strlen(sym->name)<=sNAMEMAX);
         strcpy(alias,sym->name);
       } /* if */
-      nametablesize+=strlen(alias)+1;
+      nametablesize+=(int)strlen(alias)+1;
     } /* if */
   } /* for */
   assert(numnatives==ntv_funcid);
@@ -767,7 +767,7 @@ SC_FUNC int assemble(FILE *fout,FILE *fin)
       if (constptr->value>0) {
         assert(strlen(constptr->name)>0);
         numlibraries++;
-        nametablesize+=strlen(constptr->name)+1;
+        nametablesize+=(int)strlen(constptr->name)+1;
       } /* if */
     } /* for */
   } /* if */
@@ -778,7 +778,7 @@ SC_FUNC int assemble(FILE *fout,FILE *fin)
     if ((constptr->value & PUBLICTAG)!=0) {
       assert(strlen(constptr->name)>0);
       numtags++;
-      nametablesize+=strlen(constptr->name)+1;
+      nametablesize+=(int)strlen(constptr->name)+1;
     } /* if */
   } /* for */
 
@@ -841,8 +841,8 @@ SC_FUNC int assemble(FILE *fout,FILE *fin)
       pc_resetbin(fout,hdr.publics+count*sizeof(AMX_FUNCSTUBNT));
       pc_writebin(fout,&func,sizeof func);
       pc_resetbin(fout,nameofs);
-      pc_writebin(fout,sym->name,strlen(sym->name)+1);
-      nameofs+=strlen(sym->name)+1;
+      pc_writebin(fout,sym->name,(int)strlen(sym->name)+1);
+      nameofs+=(int)strlen(sym->name)+1;
       count++;
     } /* if */
   } /* for */
@@ -890,8 +890,8 @@ SC_FUNC int assemble(FILE *fout,FILE *fin)
       pc_resetbin(fout,hdr.natives+count*sizeof(AMX_FUNCSTUBNT));
       pc_writebin(fout,&func,sizeof func);
       pc_resetbin(fout,nameofs);
-      pc_writebin(fout,alias,strlen(alias)+1);
-      nameofs+=strlen(alias)+1;
+      pc_writebin(fout,alias,(int)strlen(alias)+1);
+      nameofs+=(int)strlen(alias)+1;
       count++;
     } /* for */
     free(nativelist);
@@ -912,8 +912,8 @@ SC_FUNC int assemble(FILE *fout,FILE *fin)
         pc_resetbin(fout,hdr.libraries+count*sizeof(AMX_FUNCSTUBNT));
         pc_writebin(fout,&func,sizeof func);
         pc_resetbin(fout,nameofs);
-        pc_writebin(fout,constptr->name,strlen(constptr->name)+1);
-        nameofs+=strlen(constptr->name)+1;
+        pc_writebin(fout,constptr->name,(int)strlen(constptr->name)+1);
+        nameofs+=(int)strlen(constptr->name)+1;
         count++;
       } /* if */
     } /* for */
@@ -934,8 +934,8 @@ SC_FUNC int assemble(FILE *fout,FILE *fin)
       pc_resetbin(fout,hdr.pubvars+count*sizeof(AMX_FUNCSTUBNT));
       pc_writebin(fout,&func,sizeof func);
       pc_resetbin(fout,nameofs);
-      pc_writebin(fout,sym->name,strlen(sym->name)+1);
-      nameofs+=strlen(sym->name)+1;
+      pc_writebin(fout,sym->name,(int)strlen(sym->name)+1);
+      nameofs+=(int)strlen(sym->name)+1;
       count++;
     } /* if */
   } /* for */
@@ -954,8 +954,8 @@ SC_FUNC int assemble(FILE *fout,FILE *fin)
       pc_resetbin(fout,hdr.tags+count*sizeof(AMX_FUNCSTUBNT));
       pc_writebin(fout,&func,sizeof func);
       pc_resetbin(fout,nameofs);
-      pc_writebin(fout,constptr->name,strlen(constptr->name)+1);
-      nameofs+=strlen(constptr->name)+1;
+      pc_writebin(fout,constptr->name,(int)strlen(constptr->name)+1);
+      nameofs+=(int)strlen(constptr->name)+1;
       count++;
     } /* if */
   } /* for */
@@ -1119,7 +1119,7 @@ static void append_dbginfo(FILE *fout)
         if (prevstr!=NULL) {
           assert(prevname!=NULL);
           dbghdr.files++;
-          dbghdr.size+=sizeof(cell)+strlen(prevname)+1;
+          dbghdr.size+=(int)(sizeof(cell)+strlen(prevname)+1);
         } /* if */
         previdx=codeidx;
       } /* if */
@@ -1130,7 +1130,7 @@ static void append_dbginfo(FILE *fout)
   if (prevstr!=NULL) {
     assert(prevname!=NULL);
     dbghdr.files++;
-    dbghdr.size+=sizeof(cell)+strlen(prevname)+1;
+    dbghdr.size+=(int)(sizeof(cell)+strlen(prevname)+1);
   } /* if */
 
   /* line number table */
@@ -1151,7 +1151,7 @@ static void append_dbginfo(FILE *fout)
       dbghdr.symbols++;
       name=strchr(str+2,':');
       assert(name!=NULL);
-      dbghdr.size+=sizeof(AMX_DBG_SYMBOL)+strlen(skipwhitespace(name+1));
+      dbghdr.size+=(int)(sizeof(AMX_DBG_SYMBOL)+strlen(skipwhitespace(name+1)));
       if ((prevstr=strchr(name,'['))!=NULL)
         while ((prevstr=strchr(prevstr+1,':'))!=NULL)
           dbghdr.size+=sizeof(AMX_DBG_SYMDIM);
@@ -1162,21 +1162,21 @@ static void append_dbginfo(FILE *fout)
   for (constptr=tagname_tab.next; constptr!=NULL; constptr=constptr->next) {
     assert(strlen(constptr->name)>0);
     dbghdr.tags++;
-    dbghdr.size+=sizeof(AMX_DBG_TAG)+strlen(constptr->name);
+    dbghdr.size+=(int)(sizeof(AMX_DBG_TAG)+strlen(constptr->name));
   } /* for */
 
   /* automaton table */
   for (constptr=sc_automaton_tab.next; constptr!=NULL; constptr=constptr->next) {
     assert(constptr->index==0 && strlen(constptr->name)==0 || strlen(constptr->name)>0);
     dbghdr.automatons++;
-    dbghdr.size+=sizeof(AMX_DBG_MACHINE)+strlen(constptr->name);
+    dbghdr.size+=(int)(sizeof(AMX_DBG_MACHINE)+strlen(constptr->name));
   } /* for */
 
   /* state table */
   for (constptr=sc_state_tab.next; constptr!=NULL; constptr=constptr->next) {
     assert(strlen(constptr->name)>0);
     dbghdr.states++;
-    dbghdr.size+=sizeof(AMX_DBG_STATE)+strlen(constptr->name);
+    dbghdr.size+=(int)(sizeof(AMX_DBG_STATE)+strlen(constptr->name));
   } /* for */
 
 
@@ -1210,7 +1210,7 @@ static void append_dbginfo(FILE *fout)
             aligncell(&previdx);
           #endif
           writeerror |= !pc_writebin(fout,&previdx,sizeof previdx);
-          writeerror |= !pc_writebin(fout,prevname,strlen(prevname)+1);
+          writeerror |= !pc_writebin(fout,prevname,(int)strlen(prevname)+1);
         } /* if */
         previdx=codeidx;
       } /* if */
@@ -1224,7 +1224,7 @@ static void append_dbginfo(FILE *fout)
       aligncell(&previdx);
     #endif
     writeerror |= !pc_writebin(fout,&previdx,sizeof previdx);
-    writeerror |= !pc_writebin(fout,prevname,strlen(prevname)+1);
+    writeerror |= !pc_writebin(fout,prevname,(int)strlen(prevname)+1);
   } /* if */
 
   /* line number table */
@@ -1280,7 +1280,7 @@ static void append_dbginfo(FILE *fout)
         align16(&dbgsym.dim);
       #endif
       writeerror |= !pc_writebin(fout,&dbgsym,offsetof(AMX_DBG_SYMBOL, name));
-      writeerror |= !pc_writebin(fout,symname,strlen(symname)+1);
+      writeerror |= !pc_writebin(fout,symname,(int)strlen(symname)+1);
       for (dim=0; dim<dbgsymdim; dim++) {
         #if BYTE_ORDER==BIG_ENDIAN
           align16(&dbgidxtag[dim].tag);
@@ -1299,7 +1299,7 @@ static void append_dbginfo(FILE *fout)
       align16(&id1);
     #endif
     writeerror |= !pc_writebin(fout,&id1,sizeof id1);
-    writeerror |= !pc_writebin(fout,constptr->name,strlen(constptr->name)+1);
+    writeerror |= !pc_writebin(fout,constptr->name,(int)strlen(constptr->name)+1);
   } /* for */
 
   /* automaton table */
@@ -1313,7 +1313,7 @@ static void append_dbginfo(FILE *fout)
     #endif
     writeerror |= !pc_writebin(fout,&id1,sizeof id1);
     writeerror |= !pc_writebin(fout,&address,sizeof address);
-    writeerror |= !pc_writebin(fout,constptr->name,strlen(constptr->name)+1);
+    writeerror |= !pc_writebin(fout,constptr->name,(int)strlen(constptr->name)+1);
   } /* for */
 
   /* state table */
@@ -1328,7 +1328,7 @@ static void append_dbginfo(FILE *fout)
     #endif
     writeerror |= !pc_writebin(fout,&id1,sizeof id1);
     writeerror |= !pc_writebin(fout,&id2,sizeof id2);
-    writeerror |= !pc_writebin(fout,constptr->name,strlen(constptr->name)+1);
+    writeerror |= !pc_writebin(fout,constptr->name,(int)strlen(constptr->name)+1);
   } /* for */
 
   delete_dbgstringtable();
diff --git a/source/compiler/sc7.c b/source/compiler/sc7.c
index e460b45..8978b31 100644
--- a/source/compiler/sc7.c
+++ b/source/compiler/sc7.c
@@ -203,10 +203,10 @@ SC_FUNC void stgwrite(const char *st)
     CHECK_STGBUFFER(stgidx);
     stgbuf[stgidx++]='\0';
   } else {
-    len=(stgbuf!=NULL) ? strlen(stgbuf) : 0;
-    CHECK_STGBUFFER(len+strlen(st)+1);
+    len=(stgbuf!=NULL) ? (int)strlen(stgbuf) : 0;
+    CHECK_STGBUFFER(len+(int)strlen(st)+1);
     strcat(stgbuf,st);
-    len=strlen(stgbuf);
+    len=(int)strlen(stgbuf);
     if (len>0 && stgbuf[len-1]=='\n') {
       filewrite(stgbuf);
       stgbuf[0]='\0';
@@ -246,7 +246,7 @@ SC_FUNC void stgout(int index)
       /* there is no sense in re-optimizing if the order of the sub-expressions
        * did not change; so output directly
        */
-      for (idx=0; idx<pipeidx; idx+=strlen(stgpipe+idx)+1)
+      for (idx=0; idx<pipeidx; idx+=(int)strlen(stgpipe+idx)+1)
         filewrite(stgpipe+idx);
     } /* if */
   } /* if */
@@ -569,7 +569,7 @@ static char *replacesequence(char *pattern,char symbols[MAX_OPT_VARS][MAX_ALIAS+
       var=atoi(lptr) - 1;
       assert(var>=0 && var<MAX_OPT_VARS);
       assert(symbols[var][0]!='\0');    /* variable should be defined */
-      *repl_length+=strlen(symbols[var]);
+      *repl_length+=(int)strlen(symbols[var]);
       break;
     case '!':
       *repl_length+=3;  /* '\t', '\n' & '\0' */
diff --git a/source/compiler/sclist.c b/source/compiler/sclist.c
index d52f9f1..393aac6 100644
--- a/source/compiler/sclist.c
+++ b/source/compiler/sclist.c
@@ -213,14 +213,14 @@ SC_FUNC stringpair *insert_alias(char *name,char *alias)
   assert(strlen(name)<=sNAMEMAX);
   assert(alias!=NULL);
   assert(strlen(alias)<=sNAMEMAX);
-  if ((cur=insert_stringpair(&alias_tab,name,alias,strlen(name)))==NULL)
+  if ((cur=insert_stringpair(&alias_tab,name,alias,(int)strlen(name)))==NULL)
     error(103);       /* insufficient memory (fatal error) */
   return cur;
 }
 
 SC_FUNC int lookup_alias(char *target,char *name)
 {
-  stringpair *cur=find_stringpair(alias_tab.next,name,strlen(name));
+  stringpair *cur=find_stringpair(alias_tab.next,name,(int)strlen(name));
   if (cur!=NULL) {
     assert(strlen(cur->second)<=sNAMEMAX);
     strcpy(target,cur->second);
diff --git a/source/compiler/scmemfil.c b/source/compiler/scmemfil.c
index 4cc667d..69efaad 100644
--- a/source/compiler/scmemfil.c
+++ b/source/compiler/scmemfil.c
@@ -113,7 +113,7 @@ unsigned int mfwrite(MEMFILE *mf,const unsigned char *buffer,unsigned int size)
 
 unsigned int mfread(MEMFILE *mf,unsigned char *buffer,unsigned int size)
 {
-  return memfile_read(mf, buffer, size);
+  return (unsigned int)memfile_read(mf, buffer, size);
 }
 
 char *mfgets(MEMFILE *mf,char *string,unsigned int size)
@@ -159,7 +159,7 @@ int mfputs(MEMFILE *mf,const char *string)
 
   assert(mf!=NULL);
 
-  length=strlen(string);
+  length=(unsigned int)strlen(string);
   written=mfwrite(mf,(unsigned char *)string,length);
   return written==length;
 }