diff --git a/configure/os/CONFIG.Common.vxWorks-68040 b/configure/os/CONFIG.Common.vxWorks-68040
index 5ca818cff..07e007be7 100644
--- a/configure/os/CONFIG.Common.vxWorks-68040
+++ b/configure/os/CONFIG.Common.vxWorks-68040
@@ -19,4 +19,6 @@ ARCH_CLASS = 68k
 ARCH_DEP_CPPFLAGS = -DCPU=MC68040
 ARCH_DEP_CFLAGS = -m68040
 
+OPT_CFLAGS_YES = -O0
+
 GNU_TARGET = m68k-wrs-vxworks
diff --git a/configure/os/CONFIG.Common.vxWorks-68040lc b/configure/os/CONFIG.Common.vxWorks-68040lc
index 7d0f191a7..fd7d543b7 100644
--- a/configure/os/CONFIG.Common.vxWorks-68040lc
+++ b/configure/os/CONFIG.Common.vxWorks-68040lc
@@ -19,4 +19,6 @@ ARCH_CLASS = 68k
 ARCH_DEP_CPPFLAGS = -DCPU=MC68LC040
 ARCH_DEP_CFLAGS = -m68040 -msoft-float
 
+OPT_CFLAGS_YES = -O0
+
 GNU_TARGET = m68k-wrs-vxworks
diff --git a/configure/os/CONFIG.Common.vxWorks-68060 b/configure/os/CONFIG.Common.vxWorks-68060
index b1053a47c..b5f13165d 100644
--- a/configure/os/CONFIG.Common.vxWorks-68060
+++ b/configure/os/CONFIG.Common.vxWorks-68060
@@ -19,4 +19,6 @@ ARCH_CLASS = 68k
 ARCH_DEP_CPPFLAGS = -DCPU=MC68060
 ARCH_DEP_CFLAGS = -m68040
 
+OPT_CFLAGS_YES = -O0
+
 GNU_TARGET = m68k-wrs-vxworks