diff --git a/arch/arm/mach-omap2/sec-common.c b/arch/arm/mach-omap2/sec-common.c
index 2630e7d..674517e 100644
--- a/arch/arm/mach-omap2/sec-common.c
+++ b/arch/arm/mach-omap2/sec-common.c
@@ -130,7 +130,7 @@
 	*size = sig_addr - cert_addr;	/* Subtract out the signature size */
 	/* Subtract header if present */
 	if (strncmp((char *)sig_addr, "CERT_ISW_", 9) == 0)
-		*size = ((u32 *)*image)[HEADER_SIZE_OFFSET];
+		*size -= ((u32 *)*image)[HEADER_SIZE_OFFSET];
 	cert_size = *size;
 
 	/* Check if image load address is 32-bit aligned */