diff --git a/src/asm/make_i386_sysv_elf_gas.S b/src/asm/make_i386_sysv_elf_gas.S
index d945c0b2..9261e566 100644
--- a/src/asm/make_i386_sysv_elf_gas.S
+++ b/src/asm/make_i386_sysv_elf_gas.S
@@ -41,7 +41,7 @@ make_fcontext:
     andl  $-16, %eax
 
     /* reserve space for context-data on context-stack, and align the stack */
-    leal  -0x30(%eax), %eax
+    leal  -0x34(%eax), %eax
 
     /* third arg of make_fcontext() == address of context-function */
     /* stored in EBX */
diff --git a/src/asm/make_i386_sysv_macho_gas.S b/src/asm/make_i386_sysv_macho_gas.S
index 98e23a6e..519e4062 100644
--- a/src/asm/make_i386_sysv_macho_gas.S
+++ b/src/asm/make_i386_sysv_macho_gas.S
@@ -39,7 +39,7 @@ _make_fcontext:
     andl  $-16, %eax
 
     /* reserve space for context-data on context-stack, and align the stack */
-    leal  -0x30(%eax), %eax
+    leal  -0x34(%eax), %eax
 
     /* third arg of make_fcontext() == address of context-function */
     /* stored in EBX */