diff --git a/build/jam/ArchitectureRules b/build/jam/ArchitectureRules
index 1af07cfc30..6086d232ee 100644
--- a/build/jam/ArchitectureRules
+++ b/build/jam/ArchitectureRules
@@ -331,10 +331,6 @@ rule KernelArchitectureSetup architecture
 	HAIKU_BOOT_LINKFLAGS = ;
 	HAIKU_BOOT_LDFLAGS = -Bstatic ;
 
-	if $(gccVersion[1]) >= 4 {
-		HAIKU_KERNEL_C++FLAGS += -std=gnu++11 ;
-	}
-
 	if $(gccVersion[1]) >= 6 {
 		HAIKU_KERNEL_C++FLAGS += -fno-delete-null-pointer-checks ;
 		HAIKU_KERNEL_CCFLAGS += -fno-delete-null-pointer-checks ;
diff --git a/src/system/boot/arch/x86/Jamfile b/src/system/boot/arch/x86/Jamfile
index 4b6873580c..1e03bf70bf 100644
--- a/src/system/boot/arch/x86/Jamfile
+++ b/src/system/boot/arch/x86/Jamfile
@@ -27,7 +27,6 @@ BootMergeObject boot_arch_$(TARGET_KERNEL_ARCH).o :
 	$(kernelArchSpecificSources)
 	$(kernelLibArchSpecificSources)
 	$(librootOsArchSources)
-	: -std=c++11 # additional flags
 ;
 
 SEARCH on [ FGristFiles $(kernelArchSources) ]
diff --git a/src/system/libroot/os/arch/x86_64/Jamfile b/src/system/libroot/os/arch/x86_64/Jamfile
index 61d76d6335..86e96d19f4 100644
--- a/src/system/libroot/os/arch/x86_64/Jamfile
+++ b/src/system/libroot/os/arch/x86_64/Jamfile
@@ -1,7 +1,5 @@
 SubDir HAIKU_TOP src system libroot os arch x86_64 ;
 
-SubDirC++Flags -std=gnu++11 ;
-
 local architectureObject ;
 for architectureObject in [ MultiArchSubDirSetup x86_64 ] {
 	on $(architectureObject) {
diff --git a/src/system/libroot/os/arch/x86_64/system_time.cpp b/src/system/libroot/os/arch/x86_64/system_time.cpp
index b75991e6e1..5678d31323 100644
--- a/src/system/libroot/os/arch/x86_64/system_time.cpp
+++ b/src/system/libroot/os/arch/x86_64/system_time.cpp
@@ -6,12 +6,7 @@
 
 #include <stdint.h>
 
-// disable a warning for GCC 5.4, fixed upstream.
-// will remove the pragmas after a while.
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-variable"
 #include <x86intrin.h>
-#pragma GCC diagnostic pop
 
 
 static uint64_t cv_factor;
diff --git a/src/system/libroot/posix/malloc_debug/Jamfile b/src/system/libroot/posix/malloc_debug/Jamfile
index 0a2213d12f..f272da30ac 100644
--- a/src/system/libroot/posix/malloc_debug/Jamfile
+++ b/src/system/libroot/posix/malloc_debug/Jamfile
@@ -7,10 +7,6 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 	on $(architectureObject) {
 		local architecture = $(TARGET_PACKAGING_ARCH) ;
 
-		if $(architecture) != x86_gcc2 {
-			SubDirC++Flags -std=gnu++11 ;
-		}
-
 		UsePrivateSystemHeaders ;
 
 		MergeObject <$(architecture)>posix_malloc_debug.o :
diff --git a/src/system/libroot/posix/string/arch/x86_64/Jamfile b/src/system/libroot/posix/string/arch/x86_64/Jamfile
index b8cd49040d..e9324568a1 100644
--- a/src/system/libroot/posix/string/arch/x86_64/Jamfile
+++ b/src/system/libroot/posix/string/arch/x86_64/Jamfile
@@ -1,7 +1,5 @@
 SubDir HAIKU_TOP src system libroot posix string arch x86_64 ;
 
-SubDirC++Flags -std=gnu++11 ;
-
 local architectureObject ;
 for architectureObject in [ MultiArchSubDirSetup x86_64 ] {
 	on $(architectureObject) {