Recursive Fibonacci in Assembly

I'm attempting to implement a recursive Fibonacci program in Assembly. However, my program crashes, with an unhandled exception, and I can't seem to pick out the problem. I don't doubt that it involves my improper use of the stack, but I can't seem to point out where...

.386
.model Flat
public Fibonacci
include iosmacros.inc ;includes macros for outputting to the screen

.code
Fibonacci proc

MOV EAX, [EBP+8]
CMP EAX, 1
    JA Recurse
    MOV ECX, 1
    JMP exit

Recurse:
    DEC EAX
    MOV EDX, EAX
    PUSH EAX
    CALL Fibonacci
    ADD ESP, 4
    MOV EBX, ECX
    DEC EDX
    PUSH EDX
    CALL Fibonacci
    ADD ECX, EBX
exit:
ret
Fibonacci endp


.data


end

Also, I've pushed the number that I'm using to get the Fibonacci value to the stack in an external procedure. Any ideas where the problem might lie?