diff --git a/build-aux/build-cc.sh b/build-aux/build-cc.sh
index 2cf6e292..97f16c0d 100755
--- a/build-aux/build-cc.sh
+++ b/build-aux/build-cc.sh
@@ -25,15 +25,16 @@ if [ -n "$BUILD_DEBUG" ]; then
 fi
 
 export CC CFLAGS CPPFLAGS
+export CC_CFLAGS CC_CPPFLAGS
 
 CC=${CC-gcc}
-CFLAGS=${CFLAGS-"
+CC_CFLAGS=${CC_CFLAGS-"
 --std=gnu99
 -O0
 -g
 "}
 
-CPPFLAGS=${CPPFLAGS-"
+CC_CPPFLAGS=${CC_CPPFLAGS-"
 -D VERSION=\"$VERSION\"
 -D MODULEDIR=\"$moduledir\"
 -D PREFIX=\"$prefix\"
diff --git a/build-aux/build-cc32.sh b/build-aux/build-cc32.sh
index 24eedfa0..6ad2a73f 100755
--- a/build-aux/build-cc32.sh
+++ b/build-aux/build-cc32.sh
@@ -25,7 +25,8 @@ if [ -n "$BUILD_DEBUG" ]; then
 fi
 
 moduledir=${moduledir-${datadir}${datadir:+/}module}
-export CC32 TCC CPPFLAGS C32FLAGS
+export CC32 TCC CPPFLAGS
+export CC32 TCC CC32_CPPFLAGS CC32_CFLAGS
 
 CC32=${CC32-$(command -v i686-unknown-linux-gnu-gcc)}
 build-aux/mes-snarf.scm --mes src/gc.c
@@ -44,7 +45,7 @@ build-aux/mes-snarf.scm src/posix.c
 build-aux/mes-snarf.scm src/reader.c
 build-aux/mes-snarf.scm src/vector.c
 
-CPPFLAGS=${CPPFLAGS-"
+CC32_CPPFLAGS=${CC32_CPPFLAGS-"
 -D VERSION=\"$VERSION\"
 -D MODULEDIR=\"$moduledir\"
 -D PREFIX=\"$prefix\"
@@ -53,7 +54,7 @@ CPPFLAGS=${CPPFLAGS-"
 -I include
 "}
 
-C32FLAGS=${C32FLAGS-"
+CC32_CFLAGS=${CC32_CFLAGS-"
 -std=gnu99
 -O0
 -fno-stack-protector
diff --git a/build-aux/cc-mes.sh b/build-aux/cc-mes.sh
index 57e75f6f..3203741f 100755
--- a/build-aux/cc-mes.sh
+++ b/build-aux/cc-mes.sh
@@ -33,7 +33,7 @@ MESCC=${MESCC-$(command -v mescc)}
 MES=${MES-$(command -v mes)}
 [ -z "$MES" ] && MES=src/mes
 
-CPPFLAGS=${CPPFLAGS-"
+MES_CPPFLAGS=${MES_CPPFLAGS-"
 -D VERSION=\"$VERSION\"
 -D MODULEDIR=\"$moduledir\"
 -D PREFIX=\"$prefix\"
@@ -41,11 +41,11 @@ CPPFLAGS=${CPPFLAGS-"
 -I lib
 -I include
 "}
-MESCCFLAGS=${MESCCFLAGS-"
+MES_CCFLAGS=${MES_CCFLAGS-"
 "}
 
 if [ -n "$BUILD_DEBUG" ]; then
-    MESCCFLAGS="$MESCCFLAGS -v"
+    MES_CFLAGS="$MES_CFLAGS -v"
 fi
 
 c=$1
@@ -63,20 +63,20 @@ else
 fi
 
 if [ -n "$PREPROCESS" ]; then
-    bash $MESCC $MESCCFLAGS $CPPFLAGS -E -o "$o.E" "$c".c
-    bash $MESCC $MESCCFLAGS -S "$o".E
-    bash $MESCC $MESCCFLAGS -c -o "$o".${p}o "$o".S
+    bash $MESCC $MES_CPPFLAGS $MES_CFLAGS -E -o "$o.E" "$c".c
+    bash $MESCC $MES_CFLAGS -S "$o".E
+    bash $MESCC $MES_CFLAGS -c -o "$o".${p}o "$o".S
     if [ -z "$NOLINK" ]; then
-        bash $MESCC $MESCCFLAGS -o "$o".${p}out "$o".${p}o $MESCCLIBS
+        bash $MESCC $MES_CFLAGS -o "$o".${p}out "$o".${p}o $MES_LIBS
     fi
 elif [ -n "$COMPILE" ]; then
-    bash $MESCC $MESCCFLAGS $CPPFLAGS -S -o "$o.S" "$c".c
-    bash $MESCC $MESCCFLAGS -c -o "$o".${p}o "$o".S
+    bash $MESCC $MES_CPPFLAGS $MES_CFLAGS -S -o "$o.S" "$c".c
+    bash $MESCC $MES_CFLAGS -c -o "$o".${p}o "$o".S
     if [ -z "$NOLINK" ]; then
-        bash $MESCC $MESCCFLAGS -o "$o".${p}out "$o".${p}o $MESCCLIBS
+        bash $MESCC $MES_CFLAGS -o "$o".${p}out "$o".${p}o $MES_LIBS
     fi
 elif [ -z "$NOLINK" ]; then
-    bash $MESCC $MESCCFLAGS $CPPFLAGS -o "$o".${p}out "$c".c $MESCCLIBS
+    bash $MESCC $MES_CPPFLAGS $MES_CFLAGS -o "$o".${p}out "$c".c $MES_LIBS
 else
-    bash $MESCC $MESCCFLAGS $CPPFLAGS -c -o "$o".${p}o "$c".c
+    bash $MESCC $MES_CPPFLAGS $MES_CFLAGS -c -o "$o".${p}o "$c".c
 fi
diff --git a/build-aux/cc.sh b/build-aux/cc.sh
index 3d7a2855..d0d4eedf 100755
--- a/build-aux/cc.sh
+++ b/build-aux/cc.sh
@@ -24,7 +24,7 @@ if [ -n "$BUILD_DEBUG" ]; then
     set -x
 fi
 
-CPPFLAGS=${CPPFLAGS-"
+CC_CPPFLAGS=${CC_CPPFLAGS-"
 -D VERSION=\"$VERSION\"
 -D MODULEDIR=\"$moduledir\"
 -D PREFIX=\"$prefix\"
@@ -33,7 +33,7 @@ CPPFLAGS=${CPPFLAGS-"
 -I include
 "}
 
-CFLAGS=${CFLAGS-"
+CC_CFLAGS=${CC_CFLAGS-"
 --std=gnu99
 -O0
 -g
@@ -53,7 +53,9 @@ fi
 
 $CC\
     -c\
+    $CC_CPPFLAGS\
     $CPPFLAGS\
+    $CC_CFLAGS\
     $CFLAGS\
     -D WITH_GLIBC=1\
     -D POSIX=1\
@@ -62,6 +64,9 @@ $CC\
 
 if [ -z "$NOLINK" ]; then
     $CC\
+        $CC_CPPFLAGS\
+        $CPPFLAGS\
+        $CC_CFLAGS\
         $CFLAGS\
         -o "$o".${p}out\
         "$o".${p}o\
diff --git a/build-aux/cc32-mes.sh b/build-aux/cc32-mes.sh
index 159406dc..a6066a13 100755
--- a/build-aux/cc32-mes.sh
+++ b/build-aux/cc32-mes.sh
@@ -24,7 +24,7 @@ if [ -n "$BUILD_DEBUG" ]; then
     set -x
 fi
 
-CPPFLAGS=${CPPFLAGS-"
+CC32_CPPFLAGS=${CC32_CPPFLAGS-"
 -D VERSION=\"$VERSION\"
 -D MODULEDIR=\"$moduledir\"
 -D PREFIX=\"$prefix\"
@@ -33,7 +33,7 @@ CPPFLAGS=${CPPFLAGS-"
 -I include
 "}
 
-C32FLAGS=${C32FLAGS-"
+CC32_CFLAGS=${CC32_CFLAGS-"
 -std=gnu99
 -O0
 -fno-builtin
@@ -70,14 +70,15 @@ fi
 
 $CC32\
     -c\
-    $CPPFLAGS\
-    $C32FLAGS\
+    $CC32_CPPFLAGS\
+    $CC32_CFLAGS\
     -o "$o".${p}o\
     "$c".c
 
 if [ -z "$NOLINK" ]; then
     $CC32\
-        $C32FLAGS\
+        $CC32_CPPFLAGS\
+        $CC32_CFLAGS\
         -o "$o".${p}out\
         lib/$arch/crt1.o\
         "$o".${p}o\
diff --git a/build-aux/check-mescc.sh b/build-aux/check-mescc.sh
index 26403a31..2d594085 100755
--- a/build-aux/check-mescc.sh
+++ b/build-aux/check-mescc.sh
@@ -26,7 +26,7 @@ export BLOOD_ELF GUILE HEX2 M1 MES MESCC
 export M1FLAGS HEX2FLAGS PREPROCESS
 export MES_ARENA MES_PREFIX MES_SEED
 export BUILD_DEBUG
-export LIBC CC32LIBS MESCCLIBS
+export LIBC CC32LIBS MES_LIBS
 
 MES=${MES-src/mes}
 MESCC=${MESCC-scripts/mescc}
@@ -161,16 +161,16 @@ total=0
 for t in $tests; do
     if [ -z "${t/[012][0-9]-*/}" ]; then
         LIBC=c-mini
-        MESCCLIBS="-l c-mini"
+        MES_LIBS="-l c-mini"
     elif [ -z "${t/[78][0-9a-z]-*/}" ]; then
         LIBC=c+tcc
-        MESCCLIBS="-l c+tcc"
+        MES_LIBS="-l c+tcc"
     elif [ -z "${t/9[0-9]-*/}" ]; then
         LIBC=c+gnu
-        MESCCLIBS="-l c+gnu"
+        MES_LIBS="-l c+gnu"
     else
         LIBC=c
-        MESCCLIBS=
+        MES_LIBS=
     fi
     sh build-aux/test.sh "scaffold/tests/$t" &> scaffold/tests/"$t".log
     r=$?
@@ -279,7 +279,7 @@ broken="$broken
 #49_bracket_evaluation   ; float
 
 LIBC=c+gnu
-MESCCLIBS="-l c+gnu"
+MES_LIBS="-l c+gnu"
 
 expect=$(echo $broken | wc -w)
 ARGS="arg1 arg2 arg3 arg4 arg5"
diff --git a/build-aux/export.make b/build-aux/export.make
index b1c5eaaa..33d9cf0a 100644
--- a/build-aux/export.make
+++ b/build-aux/export.make
@@ -70,8 +70,12 @@ ifdef CFLAGS
 export CFLAGS
 endif
 
-ifdef C32FLAGS
-export C32FLAGS
+ifdef CPPFLAGS
+export CPPFLAGS
+endif
+
+ifdef CC32_CFLAGS
+export CC32_CFLAGS
 endif
 
 ifdef HEX2FLAGS
@@ -82,8 +86,8 @@ ifdef M1FLAGS
 export M1FLAGS
 endif
 
-ifdef MESCCFLAGS
-export MESCCFLAGS
+ifdef MES_CFLAGS
+export MES_CFLAGS
 endif
 
 ifdef MES_SEED
diff --git a/build-aux/test.sh b/build-aux/test.sh
index 5030f05e..4cfc0989 100755
--- a/build-aux/test.sh
+++ b/build-aux/test.sh
@@ -22,7 +22,7 @@ if [ -n "$BUILD_DEBUG" ]; then
     set -x
 fi
 
-export LIBC MESCCLIBS
+export LIBC MES_LIBS
 
 GUILE=${GUILE-$MES}
 DIFF=${DIFF-$(command -v diff)}
diff --git a/build.sh b/build.sh
index c273d62f..1da79e9c 100755
--- a/build.sh
+++ b/build.sh
@@ -42,7 +42,7 @@ datadir=${datadir-$prefix/share/mes}
 moduledir=${moduledir-${datadir}${datadir:+/}module}
 set -e
 
-CPPFLAGS=${CPPFLAGS-"
+CC_CPPFLAGS=${CC_CPPFLAGS-"
 -D VERSION=\"$VERSION\"
 -D MODULEDIR=\"$moduledir\"
 -D PREFIX=\"$prefix\"
@@ -50,12 +50,13 @@ CPPFLAGS=${CPPFLAGS-"
 -I lib
 -I include
 "}
-CFLAGS=${CFLAGS-"
+CC32_CPPFLAGS=${CC_CPPFLAGS-CC32_CPPFLAGS}
+CC_CFLAGS=${CC_CFLAGS-"
 --std=gnu99
 -O0
 -g
 "}
-C32FLAGS=${C32FLAGS-"
+CC32_FLAGS=${CC32_FLAGS-"
 --std=gnu99
 -O0
 -fno-stack-protector
@@ -64,7 +65,7 @@ C32FLAGS=${C32FLAGS-"
 -nostdinc
 -nostdlib
 "}
-MESCCLAGS=${MESCCFLAGS-"
+MES_CFLAGS=${MES_CFLAGS-"
 "}
 M1FLAGS=${M1FLAGS-"
 --LittleEndian
diff --git a/configure b/configure
index 455ad930..2584d723 100755
--- a/configure
+++ b/configure
@@ -251,9 +251,10 @@ Some influential environment variables:
   CC                C compiler command
   CFLAGS            C compiler flags
   CC32              x86 C compiler command
-  C32FLAGS          x86 C compiler flags
+  CC32_CFLAGS       x86 C compiler flags
   GUILE             guile command
   GUILE_TOOLS       guile-tools command
+  MES_CFLAGS        MesCC flags
   MES_SEED          location of mes-seed
   MESCC_TOOLS_SEED  location of mescc-tools-seed
   TCC               tcc C compiler command
@@ -288,10 +289,10 @@ Some influential environment variables:
           (HEX2 (or (getenv "HEX2") "hex2"))
           (M1 (or (getenv "M1") "M1"))
           (CFLAGS (getenv "CFLAGS"))
-          (C32FLAGS (getenv "C32FLAGS"))
+          (CC32_CFLAGS (getenv "CC32_CFLAGS"))
           (HEX2FLAGS (getenv "HEX2FLAGS"))
           (M1FLAGS (getenv "M1FLAGS"))
-          (MESCCFLAGS (getenv "MESCCFLAGS"))
+          (MES_CFLAGS (getenv "MES_CFLAGS"))
           (MES_SEED (or (getenv "MES_SEED") "../mes-seed"))
           (MESCC_TOOLS_SEED (or (getenv "MESCC_TOOLS_SEED") "../mescc-tools-seed"))
           (TINYCC_SEED (or (getenv "TINYCC_SEED") "../tinycc-seed")))
@@ -372,10 +373,10 @@ Some influential environment variables:
           (when disable-silent-rules?
             (stdout "BUILD_DEBUG:=1\n"))
           (when CFLAGS (stdout "CFLAGS:=~a\n" CFLAGS))
-          (when C32FLAGS (stdout "C32FLAGS:=~a\n" C32FLAGS))
+          (when CC32_CFLAGS (stdout "CC32_CFLAGS:=~a\n" CC32_CFLAGS))
           (when HEX2FLAGS (stdout "HEX2FLAGS:=~a\n" HEX2FLAGS))
           (when M1FLAGS (stdout "M1FLAGS:=~a\n" M1FLAGS))
-          (when MESCCFLAGS (stdout "MESCCFLAGS:=~a\n" MESCCFLAGS))))
+          (when MES_CFLAGS (stdout "MES_CFLAGS:=~a\n" MES_CFLAGS))))
       (format (current-output-port)
               "\nRun:
   ~a            to build mes