diff --git a/configure b/configure
index ba4f8721..5b582ecb 100755
--- a/configure
+++ b/configure
@@ -2473,7 +2473,7 @@ if test "$ac_cv_prog_CC" = "gcc"; then
 	if test "$with_debug" = yes; then
 		CFLAGS="${CFLAGS} -Wall"
 	else
-		CFLAGS="-O3 -Wall -fomit-frame-pointer"
+		CFLAGS="-O2 -Wall -fomit-frame-pointer"
 	fi
 fi
 if test "$on_qnx" = yes; then
diff --git a/configure.in b/configure.in
index 7a0c2a6b..a7d2c1a5 100755
--- a/configure.in
+++ b/configure.in
@@ -142,7 +142,7 @@ if test "$ac_cv_prog_CC" = "gcc"; then
 	if test "$with_debug" = yes; then
 		CFLAGS="${CFLAGS} -Wall"
 	else
-		CFLAGS="-O3 -Wall -fomit-frame-pointer"
+		CFLAGS="-O2 -Wall -fomit-frame-pointer"
 	fi
 fi
 if test "$on_qnx" = yes; then
diff --git a/os2/gccos2.mak b/os2/gccos2.mak
index ee367974..5c44ea5b 100644
--- a/os2/gccos2.mak
+++ b/os2/gccos2.mak
@@ -52,7 +52,7 @@ ifeq ($(DEBUG),Y)
 	CFLAGS  = -c -g -Wall -fomit-frame-pointer -DPDCDEBUG
 	LDFLAGS = -g
 else
-	CFLAGS  = -c -O3 -Wall -fomit-frame-pointer
+	CFLAGS  = -c -O2 -Wall -fomit-frame-pointer
 	LDFLAGS =
 endif
 
diff --git a/win32/gccwin32.mak b/win32/gccwin32.mak
index 22695b4a..72fa45f1 100644
--- a/win32/gccwin32.mak
+++ b/win32/gccwin32.mak
@@ -37,7 +37,7 @@ ifeq ($(DEBUG),Y)
 	CFLAGS  = -c -g -Wall -DPDCDEBUG
 	LDFLAGS = -g
 else
-	CFLAGS  = -c -O -Wall
+	CFLAGS  = -c -O2 -Wall
 	LDFLAGS =
 endif
 
diff --git a/win32/mingwin32.mak b/win32/mingwin32.mak
index 76908504..f0543674 100644
--- a/win32/mingwin32.mak
+++ b/win32/mingwin32.mak
@@ -37,7 +37,7 @@ ifeq ($(DEBUG),Y)
 	CFLAGS  = -c -g -Wall -DPDCDEBUG -D_NO_OLDNAMES
 	LDFLAGS = -g
 else
-	CFLAGS  = -c -O -Wall -D_NO_OLDNAMES
+	CFLAGS  = -c -O2 -Wall -D_NO_OLDNAMES
 	LDFLAGS =
 endif