diff --git a/configure.ac b/configure.ac
index e07ba4b56..7d74eba66 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1370,7 +1370,7 @@ fi
 
 # Check for libgcc symbols
 if test x"$platform" = xemu; then
-AC_CHECK_FUNCS(__udivsi3 __umodsi3 __divsi3 __modsi3 __divdi3 __moddi3 __udivdi3 __umoddi3 __ctzdi2 __ctzsi2 __aeabi_uidiv __aeabi_uidivmod __aeabi_idiv __aeabi_idivmod __aeabi_ulcmp __muldi3 __aeabi_lmul __aeabi_memcpy __aeabi_memcpy4 __aeabi_memcpy8 __aeabi_memclr __aeabi_memclr4 __aeabi_memclr8 __aeabi_memset __aeabi_lasr __aeabi_llsl __aeabi_llsr _restgpr_14_x __ucmpdi2 __ashldi3 __ashrdi3 __lshrdi3 __bswapsi2 __bswapdi2 __bzero __register_frame_info __deregister_frame_info ___chkstk_ms __chkstk_ms)
+AC_CHECK_FUNCS(__udivsi3 __umodsi3 __divsi3 __modsi3 __divdi3 __moddi3 __udivdi3 __umoddi3 __ctzdi2 __ctzsi2 __clzdi2 __aeabi_uidiv __aeabi_uidivmod __aeabi_idiv __aeabi_idivmod __aeabi_ulcmp __muldi3 __aeabi_lmul __aeabi_memcpy __aeabi_memcpy4 __aeabi_memcpy8 __aeabi_memclr __aeabi_memclr4 __aeabi_memclr8 __aeabi_memset __aeabi_lasr __aeabi_llsl __aeabi_llsr _restgpr_14_x __ucmpdi2 __ashldi3 __ashrdi3 __lshrdi3 __bswapsi2 __bswapdi2 __bzero __register_frame_info __deregister_frame_info ___chkstk_ms __chkstk_ms)
 fi
 
 if test "x$TARGET_APPLE_LINKER" = x1 ; then
diff --git a/include/grub/compiler-rt-emu.h b/include/grub/compiler-rt-emu.h
index b21425d9e..fde620ac1 100644
--- a/include/grub/compiler-rt-emu.h
+++ b/include/grub/compiler-rt-emu.h
@@ -74,6 +74,11 @@ unsigned
 EXPORT_FUNC (__ctzsi2) (grub_uint32_t x);
 #endif
 
+#ifdef HAVE___CLZDI2
+int
+EXPORT_FUNC (__clzdi2) (grub_uint64_t x);
+#endif
+
 #ifdef HAVE___AEABI_UIDIV
 grub_uint32_t
 EXPORT_FUNC (__aeabi_uidiv) (grub_uint32_t a, grub_uint32_t b);