diff --git a/configure b/configure
index 467a5866..5aa781ff 100755
--- a/configure
+++ b/configure
@@ -3221,6 +3221,8 @@ case "$host_os" in
                                                 # pick up strdup() declaration
                                                 # in <string.h>
   ;;
+  solaris* ) CFLAGS="$CFLAGS -D__EXTENSIONS__"  # for strdup() from <string.h>
+  ;;
 esac
 
 # always use ./libtool unless override from commandline (libtool=mylibtool)
diff --git a/configure.ac b/configure.ac
index 9f4590c8..81e2e464 100644
--- a/configure.ac
+++ b/configure.ac
@@ -21,7 +21,9 @@ case "$host_os" in
   linux* ) CFLAGS="$CFLAGS -D_XOPEN_SOURCE=501" # unfortunate, but needed to
                                                 # pick up strdup() declaration
                                                 # in <string.h>
-  ;;     
+  ;;
+  solaris* ) CFLAGS="$CFLAGS -D__EXTENSIONS__"  # for strdup() from <string.h>
+  ;;
 esac
 
 # always use ./libtool unless override from commandline (libtool=mylibtool)