diff --git a/CMakeLists.txt b/CMakeLists.txt
index fc330bb..d3769b1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,6 +4,7 @@ project(sugar)
 # find_package(cppfront REQUIRED)
 
 set(CMAKE_CXX_STANDARD 20)
+enable_testing()
 
 include_directories(include)
 
@@ -15,3 +16,10 @@ add_executable(sugar
         src/molasses/parser_primitives.cpp
         include/molasses/parser_primitives.h
         include/molasses/generator_primitives.h)
+
+add_test(
+        NAME id001
+        WORKING_DIRECTORY "${PROJECT_SOURCE_DIR}"
+        COMMAND expect ./tests/001.exp
+)
+set_property(TEST id001 PROPERTY ENVIRONMENT "SUGAR_EXECUTABLE=$<TARGET_FILE:sugar>")
\ No newline at end of file
diff --git a/prototypes/molasses/basic_file.mol b/prototypes/molasses/basic_file.mol
index 15e8ac1..7380e50 100644
--- a/prototypes/molasses/basic_file.mol
+++ b/prototypes/molasses/basic_file.mol
@@ -1,4 +1,5 @@
 __PROC__ main
 __--__
 __DO__
+1 i32-to-i64 30 30 + i32-to-i64 syscall1 drop_i64
 __END__
diff --git a/src/molasses/generator_primitives_x86_64_linux.cpp b/src/molasses/generator_primitives_x86_64_linux.cpp
index c059a52..9750643 100644
--- a/src/molasses/generator_primitives_x86_64_linux.cpp
+++ b/src/molasses/generator_primitives_x86_64_linux.cpp
@@ -40,7 +40,7 @@ namespace molasses {
 				std::vector<std::string>({
 					                         "    popq %rax\n",
 					                         "    popq %rbx\n",
-					                         "    multl %ebx, %eax\n",
+					                         "    imull %ebx, %eax\n",
 					                         "    andl $0xFFFFFFFF, %eax\n",
 					                         "    pushq %rax\n"
 				                         })
@@ -67,25 +67,36 @@ namespace molasses {
 				std::vector<std::string>({"i64"}),
 				std::vector<std::string>({
 					                         "    popq %rax\n",
-					                         "    movslq %rax\n",
+					                         "    movslq %eax, %rax\n",
 					                         "    pushq %rax\n"
 				                         })
 			)
 		);
 		
-		ctx.operations.emplace_back(
-			std::make_shared<molasses::primitive_operation>(
-				std::string{"syscall1"},
-				std::vector<std::string>({"i64", "i64"}),
-				std::vector<std::string>({"i64"}),
-				std::vector<std::string>({
-					                         "    popq %rax\n",
-					                         "    popq %rdi\n",
-					                         "    syscall\n",
-					                         "    pushq %rax\n"
-				                         })
-			)
-		);
+        ctx.operations.emplace_back(
+            std::make_shared<molasses::primitive_operation>(
+                std::string{"drop_i64"},
+                std::vector<std::string>({"i64"}),
+                std::vector<std::string>({}),
+                std::vector<std::string>({
+                    "    popq %rax\n"
+                })
+            )
+        );
+
+        ctx.operations.emplace_back(
+            std::make_shared<molasses::primitive_operation>(
+                std::string{"syscall1"},
+                std::vector<std::string>({"i64", "i64"}),
+                std::vector<std::string>({"i64"}),
+                std::vector<std::string>({
+                    "    popq %rax\n",
+                    "    popq %rdi\n",
+                    "    syscall\n",
+                    "    pushq %rax\n"
+                })
+            )
+        );
 		ctx.operations.emplace_back(
 			std::make_shared<molasses::primitive_operation>(
 				std::string{"syscall2"},
diff --git a/tests/001.exp b/tests/001.exp
new file mode 100644
index 0000000..a4cf4cb
--- /dev/null
+++ b/tests/001.exp
@@ -0,0 +1,45 @@
+#!/usr/bin/expect
+
+set SUGAR_EXECUTABLE $::env(SUGAR_EXECUTABLE)
+
+proc abort {reason} {
+    puts "test failed $reason"
+    exit 1
+}
+
+spawn -noecho $SUGAR_EXECUTABLE tests/001/exit-with-1.mol lex parse
+expect {
+    error { abort "failed to parse" }
+    eof { abort "cannot find the main" }
+    main
+}
+expect eof
+lassign [wait] pid spawnid os_error_flag value
+if {$value != 0} {
+    abort "compiler crashed"
+}
+
+
+spawn -noecho $SUGAR_EXECUTABLE tests/001/exit-with-1.mol lex parse /tmp/sugar.generated generate assemble
+expect {
+    error { abort "failed to compile" }
+    eof { abort "didn't run clang" }
+    clang
+}
+expect {
+    error { abort "failed to link" }
+    eof { abort "didn't run ld" }
+    ld
+}
+expect eof
+lassign [wait] pid spawnid os_error_flag value
+if {$value != 0} {
+    abort "compiler crashed"
+}
+
+spawn -noecho /tmp/sugar.generated
+expect eof
+lassign [wait] pid spawnid os_error_flag value
+if {$value != 1} {
+    abort "executable didn't return exit code 1 but $value instead"
+}
\ No newline at end of file
diff --git a/tests/001/exit-with-1.mol b/tests/001/exit-with-1.mol
new file mode 100644
index 0000000..7380e50
--- /dev/null
+++ b/tests/001/exit-with-1.mol
@@ -0,0 +1,5 @@
+__PROC__ main
+__--__
+__DO__
+1 i32-to-i64 30 30 + i32-to-i64 syscall1 drop_i64
+__END__