diff --git a/build-aux/build.sh.in b/build-aux/build.sh.in
index 13952a90..e86990c6 100644
--- a/build-aux/build.sh.in
+++ b/build-aux/build.sh.in
@@ -51,40 +51,40 @@ fi
 debug=
 #debug=-g
 
-CFLAGS="
+AM_CFLAGS="
 -static
 $debug
 "
 
 if test $mes_libc = mes; then
-    CFLAGS="$CFLAGS
+    AM_CFLAGS="$AM_CFLAGS
 -nostdinc
 -nostdlib
 -fno-builtin
 "
 fi
 
-CPPFLAGS="
+AM_CPPFLAGS="
 -D HAVE_CONFIG_H=1
 -I ../include
 -I ${srcdir}/../include
 -I ${srcdir}/../include/$mes_kernel/$mes_cpu
 "
 
-LDFLAGS="
+AM_LDFLAGS="
 $debug
 -L .
 "
 if test $mes_libc = mes; then
-    LDFLAGS="$LDFLAGS
+    AM_LDFLAGS="$AM_LDFLAGS
 -nostdlib
 "
 fi
 LIBS=-lc
 
-export CFLAGS
-export CPPFLAGS
-export LDFLAGS
+export AM_CFLAGS CFLAGS
+export AM_CPPFLAGS CPPFLAGS
+export AM_LDFLAGS LDFLAGS
 export LIBS
 
 (
@@ -96,7 +96,7 @@ export LIBS
         srcdir=../
     fi
     if test $compiler = gcc; then
-        CPPFLAGS="
+        AM_CPPFLAGS="
 -D HAVE_CONFIG_H=1
 -I include
 -I ${srcdest}include
@@ -110,12 +110,12 @@ export LIBS
 
 (
     if test $compiler = gcc; then
-        LDFLAGS="$LDFLAGS
+        AM_LDFLAGS="$AM_LDFLAGS
 -L gcc-lib
 "
     fi
 
-    CPPFLAGS="
+    AM_CPPFLAGS="
 -D HAVE_CONFIG_H=1
 -I include
 -I ${srcdest}include
@@ -136,7 +136,7 @@ export LIBS
         srcdest=../
         srcdir=../
     fi
-        CPPFLAGS="
+        AM_CPPFLAGS="
 -D HAVE_CONFIG_H=1
 -I include
 -I ${srcdest}include
@@ -145,6 +145,10 @@ export LIBS
     compiler=mescc
     AR="${srcdest}pre-inst-env mesar"
     CC="${srcdest}pre-inst-env mescc -m $mes_bits"
+    # No user overrides for MesCC, they are probably intended for GCC
+    CFLAGS=
+    CPPFLAGS=
+    LDFLAGS=
     ${SHELL} ${srcdest}build-aux/build-lib.sh
     ${SHELL} ${srcdest}build-aux/build-source-lib.sh
 )
diff --git a/build-aux/cc.sh b/build-aux/cc.sh
index 93ae07ba..28a21802 100755
--- a/build-aux/cc.sh
+++ b/build-aux/cc.sh
@@ -23,8 +23,8 @@ compile () {
     o=$b.o
     objects="$objects $o"
     if test $c -nt $o; then
-        trace "CC         $c" $CC -c $CPPFLAGS $CFLAGS -o $o $c
-        $CC -c $CPPFLAGS $CFLAGS -o $o $c
+        trace "CC         $c" $CC -c $AM_CPPFLAGS $CPPFLAGS $AM_CFLAGS $CFLAGS -o $o $c
+        $CC -c $AM_CPPFLAGS $CPPFLAGS $AM_CFLAGS $CFLAGS -o $o $c
     fi
 }
 
@@ -51,6 +51,6 @@ link () {
     else
         crt1=crt1.o
     fi
-    trace "CCLD       $out" $CC $CFLAGS $LDFLAGS -o $out $crt1 $objects $LIBS
+    trace "CCLD       $out" $CC $AM_CFLAGS $CFLAGS $AM_LDFLAGS $LDFLAGS -o $out $crt1 $objects $LIBS
     objects=
 }
diff --git a/build-aux/config.make.in b/build-aux/config.make.in
index 45947ef8..1d8e4087 100644
--- a/build-aux/config.make.in
+++ b/build-aux/config.make.in
@@ -20,6 +20,8 @@ AR:=@AR@
 BASH:=@BASH@
 BLOOD_ELF:=@BLOOD_ELF@
 CC:=@CC@
+CFLAGS:=@CFLAGS@
+CPPFLAGS:=@CPPFLAGS@
 DIFF:=@DIFF@
 DOT:=@DOT@
 GIT:=@GIT@
@@ -29,6 +31,7 @@ GUILE_EFFECTIVE_VERSION:=@GUILE_EFFECTIVE_VERSION@
 GUIX:=@GUIX@
 HELP2MAN:=@HELP2MAN@
 HEX2:=@HEX2@
+LDFLAGS:=@LDFLAGS@
 MAKEINFO:=@MAKEINFO@
 M1:=@M1@
 MES_FOR_BUILD:=@MES_FOR_BUILD@
diff --git a/build-aux/config.sh.in b/build-aux/config.sh.in
index 83fa015d..29006499 100644
--- a/build-aux/config.sh.in
+++ b/build-aux/config.sh.in
@@ -21,6 +21,8 @@ AR=${AR-"@AR@"}
 BASH="@BASH@"
 BLOOD_ELF="@BLOOD_ELF@"
 CC=${CC-"@CC@"}
+CFLAGS=${CFLAGS-"@CFLAGS@"}
+CPPFLAGS=${CPPFLAGS-"@CPPFLAGS@"}
 DIFF=${DIFF-@DIFF@}
 DOT="@DOT@"
 GIT="@GIT@"
@@ -30,6 +32,7 @@ GUILE_EFFECTIVE_VERSION="@GUILE_EFFECTIVE_VERSION@"
 GUIX="@GUIX@"
 HELP2MAN="@HELP2MAN@"
 HEX2="@HEX2@"
+LDFLAGS=${LDFLAGS-"@LDFLAGS@"}
 MAKEINFO="@MAKEINFO@"
 M1="@M1@"
 MES_FOR_BUILD="@MES_FOR_BUILD@"
diff --git a/build-aux/export.make b/build-aux/export.make
index f3807af7..6876c8e4 100644
--- a/build-aux/export.make
+++ b/build-aux/export.make
@@ -131,6 +131,18 @@ ifdef GUILE_LOAD_COMPILED_PATH
 export GUILE_LOAD_COMPILED_PATH
 endif
 
+ifdef AM_CFLAGS
+export AM_CFLAGS
+endif
+
+ifdef AM_CPPFLAGS
+export AM_CPPFLAGS
+endif
+
+ifdef AM_LDFLAGS
+export AM_LDFLAGS
+endif
+
 ifdef CFLAGS
 export CFLAGS
 endif
@@ -139,6 +151,10 @@ ifdef CPPFLAGS
 export CPPFLAGS
 endif
 
+ifdef LDFLAGS
+export LDFLAGS
+endif
+
 ifdef HEX2FLAGS
 export HEX2FLAGS
 endif
diff --git a/build-aux/test-c.sh b/build-aux/test-c.sh
index 9a84f6c4..49c6f385 100755
--- a/build-aux/test-c.sh
+++ b/build-aux/test-c.sh
@@ -59,8 +59,8 @@ else
     crt1=crt1.o
 fi
 
-$CC -c $CPPFLAGS $CFLAGS -o "$o".o "$t"
-$CC $CFLAGS $LDFLAGS -L . -o "$o" $crt1 "$o".o $LIBS
+$CC -g -c $AM_CPPFLAGS $CPPFLAGS $AM_CFLAGS $CFLAGS -o "$o".o "$t"
+$CC -g $AM_CFLAGS $CFLAGS $AM_LDFLAGS $LDFLAGS -L . -o "$o" $crt1 "$o".o $LIBS
 
 set +e
 timeout 10 "$o" -s --long file0 file1 > "$o".1 2> "$o".2
diff --git a/configure b/configure
index 44c44cb2..8edb2ce7 100755
--- a/configure
+++ b/configure
@@ -612,6 +612,8 @@ See \"Porting GNU Mes\" in the manual, or try --with-courage\n" mes-system)
                      ("@SHELL@" . ,shell)
 
                      ("@CFLAGS@" . ,(or (getenv "CFLAGS") ""))
+                     ("@CPPFLAGS@" . ,(or (getenv "CPPFLAGS") ""))
+                     ("@LDFLAGS@" . ,(or (getenv "LDFLAGS") ""))
                      ("@HEX2FLAGS@" . ,(or (getenv "HEX2FLAGS") ""))
                      ("@M1FLAGS@" . ,(or (getenv "M1FLAGS") ""))
 
diff --git a/configure.sh b/configure.sh
index edf57789..947ddd85 100755
--- a/configure.sh
+++ b/configure.sh
@@ -58,6 +58,8 @@ AR=${AR-$(command -v ar)} || true
 BASH=${BASH-$(command -v bash)}
 BLOOD_ELF=${BLOOD_ELF-$(command -v blood-elf)}
 CC=${CC-$(command -v gcc)} || true
+CFLAGS=${CFLAGS-}
+CPPFLAGS=${CPPFLAGS-}
 DIFF=${DIFF-$(command -v diff || echo $PWD/pre-inst-env diff.scm)}
 GUILD=${GUILD-$(command -v guild)} || true
 GUILE_TOOLS=${GUILE_TOOLS-$(command -v guile-tools)} || true
@@ -70,6 +72,7 @@ if test ! "$GUILD"; then
 fi
 GUILE=${GUILE-$(command -v guile)} || true
 HEX2=${HEX2-$(command -v hex2)}
+LDPFLAGS=${LDFLAGS-}
 M1=${M1-$(command -v M1)}
 MES_FOR_BUILD=${MES_FOR_BUILD-$(command -v mes || command -v guile || echo mes)}
 GIT=${GIT-$(command -v git)} || true