diff --git a/Makefile b/Makefile
index fc7d85f11..6d3f15651 100644
--- a/Makefile
+++ b/Makefile
@@ -97,6 +97,11 @@ LD = $(CC)
 # Those flags only feed CFLAGS so it is not mandatory to use this form.
 DEBUG_CFLAGS = -g
 
+#### Compiler-specific flags that may be used to disable some negative over-
+# optimization or to silence some warnings. -fno-strict-aliasing is needed with
+# gcc >= 4.4.
+SPEC_CFLAGS = -fno-strict-aliasing
+
 #### Memory usage tuning
 # If small memory footprint is required, you can reduce the buffer size. There
 # are 2 buffers per concurrent session, so 16 kB buffers will eat 32 MB memory
@@ -154,7 +159,7 @@ ARCH_FLAGS        = $(ARCH_FLAGS.$(ARCH))
 # These CFLAGS contain general optimization options, CPU-specific optimizations
 # and debug flags. They may be overridden by some distributions which prefer to
 # set all of them at once instead of playing with the CPU and DEBUG variables.
-CFLAGS = $(ARCH_FLAGS) $(CPU_CFLAGS) $(DEBUG_CFLAGS)
+CFLAGS = $(ARCH_FLAGS) $(CPU_CFLAGS) $(DEBUG_CFLAGS) $(SPEC_CFLAGS)
 
 #### Common LDFLAGS
 # These LDFLAGS are used as the first "ld" options, regardless of any library
diff --git a/Makefile.bsd b/Makefile.bsd
index 502783043..1ce871b72 100644
--- a/Makefile.bsd
+++ b/Makefile.bsd
@@ -86,6 +86,7 @@ DLMALLOC_THRES=4096
 TARGET_OPTS=$(COPTS.$(TARGET))
 REGEX_OPTS=$(COPTS.$(REGEX))
 CPU_OPTS=$(COPTS.$(CPU))
+SPEC_OPTS=-fno-strict-aliasing
 
 VERSION != cat VERSION 2>/dev/null || touch VERSION
 SUBVERS != cat SUBVERS 2>/dev/null || touch SUBVERS
@@ -98,7 +99,7 @@ VER_OPTS := -DCONFIG_HAPROXY_VERSION=\"$(VERSION)$(SUBVERS)\" \
 EBTREE_DIR := ebtree
 
 COPTS   = -Iinclude -I$(EBTREE_DIR) $(ADDINC) $(CPU_OPTS) $(TARGET_OPTS) \
-          $(REGEX_OPTS) $(SMALL_OPTS) $(VER_OPTS) $(DEFINE)
+          $(SPEC_OPTS) $(REGEX_OPTS) $(SMALL_OPTS) $(VER_OPTS) $(DEFINE)
 LIBS    = $(LIBS.$(TARGET)) $(LIBS.$(REGEX)) $(ADDLIB)
 CFLAGS  = -Wall $(COPTS) $(DEBUG)
 LDFLAGS = -g
diff --git a/Makefile.osx b/Makefile.osx
index ab15e1076..f60508e99 100644
--- a/Makefile.osx
+++ b/Makefile.osx
@@ -86,6 +86,7 @@ DLMALLOC_THRES=4096
 TARGET_OPTS=$(COPTS.$(TARGET))
 REGEX_OPTS=$(COPTS.$(REGEX))
 CPU_OPTS=$(COPTS.$(CPU))
+SPEC_OPTS=-fno-strict-aliasing
 
 VERSION != cat VERSION 2>/dev/null || touch VERSION
 SUBVERS != cat SUBVERS 2>/dev/null || touch SUBVERS
@@ -95,7 +96,7 @@ VER_OPTS := -DCONFIG_HAPROXY_VERSION=\"$(VERSION)$(SUBVERS)\" \
             -DCONFIG_HAPROXY_DATE=\"$(VERDATE)\"
 
 COPTS   = -Iinclude -I$(EBTREE_DIR) $(ADDINC) $(CPU_OPTS) $(TARGET_OPTS) \
-          $(REGEX_OPTS) $(SMALL_OPTS) $(VER_OPTS) $(DEFINE)
+          $(SPEC_OPTS) $(REGEX_OPTS) $(SMALL_OPTS) $(VER_OPTS) $(DEFINE)
 LIBS    = $(LIBS.$(TARGET)) $(LIBS.$(REGEX)) $(ADDLIB)
 CFLAGS  = -Wall $(COPTS) $(DEBUG) -isysroot /Developer/SDKs/MacOSX10.4u.sdk -arch ppc -arch i386 -mmacosx-version-min=10.4
 LDFLAGS = -g -isysroot /Developer/SDKs/MacOSX10.4u.sdk -arch ppc -arch i386 -mmacosx-version-min=10.4