diff --git a/Makefile b/Makefile
index 877e0b8a66..957fadc57c 100644
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,8 @@
 # Define NO_CURL if you do not have curl installed.  git-http-pull is not
 # built, and you cannot use http:// and https:// transports.
 #
+# Define NO_STRCASESTR if you don't have strcasestr.
+#
 # Define PPC_SHA1 environment variable when running make to make use of
 # a bundled SHA1 routine optimized for PowerPC.
 #
@@ -203,6 +205,10 @@ ifdef NEEDS_NSL
 	LIBS += -lnsl
 	SIMPLE_LIB += -lnsl
 endif
+ifdef NO_STRCASESTR
+	DEFINES += -Dstrcasestr=gitstrcasestr
+	LIB_OBJS += compat/strcasestr.o
+endif
 
 DEFINES += '-DSHA1_HEADER=$(SHA1_HEADER)'
 
diff --git a/compat/strcasestr.c b/compat/strcasestr.c
new file mode 100644
index 0000000000..b96414d36b
--- /dev/null
+++ b/compat/strcasestr.c
@@ -0,0 +1,23 @@
+#include <string.h>
+#include <ctype.h>
+
+char *gitstrcasestr(const char *haystack, const char *needle)
+{
+	int nlen = strlen(needle);
+	int hlen = strlen(haystack) - nlen + 1;
+	int i;
+
+	for (i = 0; i < hlen; i++) {
+		int j;
+		for (j = 0; j < nlen; j++) {
+			unsigned char c1 = haystack[i+j];
+			unsigned char c2 = needle[j];
+			if (toupper(c1) != toupper(c2))
+				goto next;
+		}
+		return (char *) haystack + i;
+	next:
+		;
+	}
+	return NULL;
+}