diff --git a/config-mingw b/config-mingw
index 0d630101..4dfe2cf2 100755
--- a/config-mingw
+++ b/config-mingw
@@ -1,7 +1,7 @@
 #!/bin/sh
 set -e
 set -x
-if echo $PATH | grep -q /mingw64; then
+if g++ -v 2>&1 | grep Target: | grep -q x86_64; then
     wordsize=64
 else
     wordsize=32
diff --git a/config-msvc b/config-msvc
index 56d752e4..36c4aab2 100755
--- a/config-msvc
+++ b/config-msvc
@@ -1,7 +1,7 @@
 #!/bin/sh
 set -e
 set -x
-if echo $PATH | grep -q /mingw64; then
+if cl 2>&1 | grep -q 'for x64'; then
     wordsize=64
 else
     wordsize=32