diff --git a/src/codegen/fasm.rs b/src/codegen/fasm.rs
index 224c5cd..d1901e3 100644
--- a/src/codegen/fasm.rs
+++ b/src/codegen/fasm.rs
@@ -58,42 +58,42 @@ pub fn fasm_codegen(exprs: &Vec<Expr>, not_a_function: bool) -> String {
 		    match i {
 			0 => {
 			    // First parameter. Put in %rdi.
-			    asm_start.push_str(format!("\tmov rdi, {}\n", p.value.unwrap()).as_str());
+			    asm_start.push_str(format!("\tmov rdi, {}\n", p.unwrap()).as_str());
 			},
 
 			1 => {
 			    // Second parameter. Put in %rsi.
-			    asm_start.push_str(format!("\tmov rsi, {}\n", p.value.unwrap()).as_str());
+			    asm_start.push_str(format!("\tmov rsi, {}\n", p.unwrap()).as_str());
 			},
 
 			2 => {
 			    // Third parameter. Put in %rdx.
-			    asm_start.push_str(format!("\tmov rdx, {}\n", p.value.unwrap()).as_str());
+			    asm_start.push_str(format!("\tmov rdx, {}\n", p.unwrap()).as_str());
 			},
 
 			3 => {
 			    // Fourth parameter. Put in %rcx.
-			    asm_start.push_str(format!("\tmov rcx, {}\n", p.value.unwrap()).as_str());
+			    asm_start.push_str(format!("\tmov rcx, {}\n", p.unwrap()).as_str());
 			},
 
 			4 => {
 			    // Fifth parameter. Put in %r8.
-			    asm_start.push_str(format!("\tmov r8, {}\n", p.value.unwrap()).as_str());
+			    asm_start.push_str(format!("\tmov r8, {}\n", p.unwrap()).as_str());
 			},
 
 			5 => {
 			    // Sixth parameter. Put in %r9.
-			    asm_start.push_str(format!("\tmov r9, {}\n", p.value.unwrap()).as_str());
+			    asm_start.push_str(format!("\tmov r9, {}\n", p.unwrap()).as_str());
 			},
 
 			_ => {
 			    // Parameters after the sixth parameter are pushed to the stack.
-			    asm_start.push_str(format!("\tpush {}\n", p.value.unwrap()).as_str());
+			    asm_start.push_str(format!("\tpush {}\n", p.unwrap()).as_str());
 			}
 		    }
 		}
 
-		asm_start.push_str(format!("call {}", e.name).as_str());
+		asm_start.push_str(format!("\tcall {}\n", e.name).as_str());
 	    },
 
 	    Expr::VarDefinition(e) => {
@@ -111,6 +111,7 @@ pub fn fasm_codegen(exprs: &Vec<Expr>, not_a_function: bool) -> String {
             Expr::FunDefinition(e) => {
                 asm_text.push_str(format!("{}:\n", e.name).as_str());
 	        asm_text.push_str(fasm_codegen(&e.contents, false).as_str());
+                asm_text.push_str("\tret\n");
             }
 
 	    _ => break,
@@ -118,12 +119,12 @@ pub fn fasm_codegen(exprs: &Vec<Expr>, not_a_function: bool) -> String {
         
     }
     
-    if not_a_function {
-	asm_start.push_str("\tmov rax, 60    ; 60 is the system call number for exit.\n");
-	asm_start.push_str("\txor rdi, rdi   ; 0 is the exit code we want.\n");
-	asm_start.push_str("\tsyscall        ; this is the instruction to actually perform the system call.\n");
-    }
 
+    if not_a_function {
+        asm_start.push_str("\tmov rax, 60    ; 60 is the system call number for exit.\n");
+        asm_start.push_str("\txor rdi, rdi   ; 0 is the exit code we want.\n");
+        asm_start.push_str("\tsyscall        ; this is the instruction to actually perform the system call.\n");
+    }
     let asm = format!("{}{}{}", asm_start, asm_text, asm_data);
     asm
 }
diff --git a/src/main.rs b/src/main.rs
index ea39b7c..36dd435 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -18,16 +18,25 @@ fn main() {
                               ),
                               Expr::FunDefinition(FunDefinition {
                                   name: "adder", contents: vec![
-                                      Expr::Return(Value::Math(
+                                      Expr::MathExpr(
                                           Math {
                                               left: &Value::Param(ParamReference {param_number: 0}),
                                               right: &Value::Param(ParamReference {param_number: 1}),
                                               operator: MathOperator::OP_ADD
                                           }
-                                      ))
+                                      )
                                   ]
                               }),
-                              Expr::Breakpoint],
+
+                              Expr::FunCall(
+                                  FunCall {
+                                      name: "adder",
+                                      params: vec![Value::Var(VarReference {name: "goren"}), Value::Number(6)]
+                                  }
+                              ),
+                              
+                              Expr::Breakpoint
+                          ],
                           true
     );
     println!("{}", fc);
diff --git a/src/parse/ast.rs b/src/parse/ast.rs
index 5bf5acb..3973551 100644
--- a/src/parse/ast.rs
+++ b/src/parse/ast.rs
@@ -31,7 +31,7 @@ pub enum MathOperator {
 #[derive(Debug)]
 pub struct FunCall<'a> {
     pub name: &'a str,
-    pub params: Vec<FunParamCall<'a>>,
+    pub params: Vec<Value<'a>>,
 }
 
 #[derive(Debug)]
@@ -75,7 +75,6 @@ pub enum Value<'a> {
     Var(VarReference<'a>),
     Param(ParamReference),
     Number(u64),
-    Math(Math<'a>),
 }
 
 impl<'a> Value<'a> {
@@ -100,10 +99,6 @@ impl<'a> Value<'a> {
 	    Value::Var(e) => {
 		return format!("[{}]", e.name.to_string());
 	    },
-
-            Value::Math(e) => {
-                return String::from("rax");
-            }
 	}
     }
 }