diff --git a/cmake/QtBuild.cmake b/cmake/QtBuild.cmake
index 5c03c433e3f..e62294c0455 100644
--- a/cmake/QtBuild.cmake
+++ b/cmake/QtBuild.cmake
@@ -326,7 +326,7 @@ elseif(QNX)
     set(compiler_x86-64 x86_64)
     set(compiler_x86 x86)
     foreach(arch aarch64le armle-v7 x86-64 x86)
-        if (CMAKE_CXX_COMPILER_TARGET MATCHES "${compiler_${arch}}")
+        if (CMAKE_CXX_COMPILER_TARGET MATCHES "${compiler_${arch}}$")
             set(QT_DEFAULT_MKSPEC qnx-${arch}-qcc)
         endif()
     endforeach()
diff --git a/cmake/QtCompilerOptimization.cmake b/cmake/QtCompilerOptimization.cmake
index 333cbf3f155..ed6921da532 100644
--- a/cmake/QtCompilerOptimization.cmake
+++ b/cmake/QtCompilerOptimization.cmake
@@ -6,6 +6,7 @@ if (QCC)
     set(QT_CFLAGS_SSE4_2    "-msse4.2")
     set(QT_CFLAGS_AVX       "-mavx")
     set(QT_CFLAGS_AVX2      "-mavx2")
+    set(QT_CFLAGS_ARCH_HASWELL "-march=haswell")
     set(QT_CFLAGS_AESNI     "-maes")
     set(QT_CFLAGS_SHANI     "-msha")
 endif()
diff --git a/mkspecs/common/qcc-base-qnx-aarch64le.conf b/mkspecs/common/qcc-base-qnx-aarch64le.conf
index 914ef33f374..92eff229544 100644
--- a/mkspecs/common/qcc-base-qnx-aarch64le.conf
+++ b/mkspecs/common/qcc-base-qnx-aarch64le.conf
@@ -8,7 +8,7 @@ include(g++-unix.conf)
 include(unix.conf)
 
 QMAKE_CC                = qcc -Vgcc_ntoaarch64le
-QMAKE_CXX               = qcc -Vgcc_ntoaarch64le
+QMAKE_CXX               = q++ -Vgcc_ntoaarch64le
 QNX_CPUDIR              = aarch64le
 
 include(qcc-base-qnx.conf)
diff --git a/mkspecs/common/qcc-base-qnx-armle-v7.conf b/mkspecs/common/qcc-base-qnx-armle-v7.conf
index ad3bb33da4a..25b8bbc808c 100644
--- a/mkspecs/common/qcc-base-qnx-armle-v7.conf
+++ b/mkspecs/common/qcc-base-qnx-armle-v7.conf
@@ -9,7 +9,7 @@ include(unix.conf)
 include(g++-unix.conf)
 
 QMAKE_CC                = qcc -Vgcc_ntoarmv7le
-QMAKE_CXX               = qcc -Vgcc_ntoarmv7le
+QMAKE_CXX               = q++ -Vgcc_ntoarmv7le
 QNX_CPUDIR              = armle-v7
 QMAKE_CFLAGS           += -mfpu=neon
 
diff --git a/mkspecs/common/qcc-base-qnx-x86-64.conf b/mkspecs/common/qcc-base-qnx-x86-64.conf
index fd04104f718..8e77b5b6600 100644
--- a/mkspecs/common/qcc-base-qnx-x86-64.conf
+++ b/mkspecs/common/qcc-base-qnx-x86-64.conf
@@ -8,7 +8,7 @@ include(g++-unix.conf)
 include(unix.conf)
 
 QMAKE_CC                = qcc -Vgcc_ntox86_64
-QMAKE_CXX               = qcc -Vgcc_ntox86_64
+QMAKE_CXX               = q++ -Vgcc_ntox86_64
 QNX_CPUDIR              = x86_64
 
 include(qcc-base-qnx.conf)
diff --git a/mkspecs/common/qcc-base-qnx-x86.conf b/mkspecs/common/qcc-base-qnx-x86.conf
index 37a5d9ce704..23bc84c3c85 100644
--- a/mkspecs/common/qcc-base-qnx-x86.conf
+++ b/mkspecs/common/qcc-base-qnx-x86.conf
@@ -9,7 +9,7 @@ include(unix.conf)
 include(g++-unix.conf)
 
 QMAKE_CC                = qcc -Vgcc_ntox86
-QMAKE_CXX               = qcc -Vgcc_ntox86
+QMAKE_CXX               = q++ -Vgcc_ntox86
 QNX_CPUDIR              = x86
 
 include(qcc-base-qnx.conf)
diff --git a/mkspecs/common/qcc-base.conf b/mkspecs/common/qcc-base.conf
index 24ee29b6b8a..b13e3b55bdf 100644
--- a/mkspecs/common/qcc-base.conf
+++ b/mkspecs/common/qcc-base.conf
@@ -38,7 +38,6 @@ QMAKE_CFLAGS_SHANI     += -msha
 
 QMAKE_CFLAGS_STACK_PROTECTOR_STRONG = -fstack-protector-strong
 
-QMAKE_CXXFLAGS         += $$QMAKE_CFLAGS -lang-c++
 QMAKE_CXXFLAGS_DEPS    += $$QMAKE_CFLAGS_DEPS
 QMAKE_CXXFLAGS_WARN_ON += $$QMAKE_CFLAGS_WARN_ON
 QMAKE_CXXFLAGS_WARN_OFF += $$QMAKE_CFLAGS_WARN_OFF
@@ -56,4 +55,3 @@ QMAKE_CFLAGS_USE_PRECOMPILE   = -Wc,-include -Wc,${QMAKE_PCH_OUTPUT_BASE}
 QMAKE_CXXFLAGS_PRECOMPILE     = -x c++-header -c ${QMAKE_PCH_INPUT} -o ${QMAKE_PCH_OUTPUT}
 QMAKE_CXXFLAGS_USE_PRECOMPILE = $$QMAKE_CFLAGS_USE_PRECOMPILE
 
-QMAKE_LFLAGS           += -lang-c++