diff --git a/cmake/QtPublicSbomHelpers.cmake b/cmake/QtPublicSbomHelpers.cmake
index f82eeac712a..49056a6c015 100644
--- a/cmake/QtPublicSbomHelpers.cmake
+++ b/cmake/QtPublicSbomHelpers.cmake
@@ -1548,9 +1548,13 @@ function(_qt_internal_sbom_map_path_to_reproducible_relative_path out_var)
     else()
         if(IS_ABSOLUTE "${path}")
             set(path_in "${path}")
-            if(path MATCHES "^${PROJECT_SOURCE_DIR}/")
+
+            string(FIND "${path}" "${PROJECT_SOURCE_DIR}/" src_idx)
+            string(FIND "${path}" "${PROJECT_BINARY_DIR}/" dest_idx)
+
+            if(src_idx EQUAL "0")
                 set(is_in_source_dir TRUE)
-            elseif(path MATCHES "^${PROJECT_BINARY_DIR}/")
+            elseif(dest_idx EQUAL "0")
                 set(is_in_build_dir TRUE)
             endif()
         else()