diff --git a/build/autoconf/mozprog.m4 b/build/autoconf/mozprog.m4
index 7bafa4cdd49..00e8dd9177c 100644
--- a/build/autoconf/mozprog.m4
+++ b/build/autoconf/mozprog.m4
@@ -48,7 +48,7 @@ AC_DEFUN(MOZ_PATH_PROG,
   if test "$msyshost"; then
     case "[$]$1" in
     /*)
-      $1="$(cd "$(dirname "[$]$1")" && pwd -W)/$(basename "[$]$1")"
+      $1="$(cd \"$(dirname \"[$]$1\")\" && pwd -W)/$(basename \"[$]$1\")"
       if test -e "[$]$1.exe"; then
         $1="[$]$1.exe"
       fi
@@ -61,7 +61,7 @@ AC_DEFUN(MOZ_PATH_PROGS,
   if test "$msyshost"; then
     case "[$]$1" in
     /*)
-      $1="$(cd "$(dirname "[$]$1")" && pwd -W)/$(basename "[$]$1")"
+      $1="$(cd \"$(dirname \"[$]$1\")\" && pwd -W)/$(basename \"[$]$1\")"
       if test -e "[$]$1.exe"; then
         $1="[$]$1.exe"
       fi
diff --git a/js/src/build/autoconf/mozprog.m4 b/js/src/build/autoconf/mozprog.m4
index 7bafa4cdd49..00e8dd9177c 100644
--- a/js/src/build/autoconf/mozprog.m4
+++ b/js/src/build/autoconf/mozprog.m4
@@ -48,7 +48,7 @@ AC_DEFUN(MOZ_PATH_PROG,
   if test "$msyshost"; then
     case "[$]$1" in
     /*)
-      $1="$(cd "$(dirname "[$]$1")" && pwd -W)/$(basename "[$]$1")"
+      $1="$(cd \"$(dirname \"[$]$1\")\" && pwd -W)/$(basename \"[$]$1\")"
       if test -e "[$]$1.exe"; then
         $1="[$]$1.exe"
       fi
@@ -61,7 +61,7 @@ AC_DEFUN(MOZ_PATH_PROGS,
   if test "$msyshost"; then
     case "[$]$1" in
     /*)
-      $1="$(cd "$(dirname "[$]$1")" && pwd -W)/$(basename "[$]$1")"
+      $1="$(cd \"$(dirname \"[$]$1\")\" && pwd -W)/$(basename \"[$]$1\")"
       if test -e "[$]$1.exe"; then
         $1="[$]$1.exe"
       fi