diff --git a/fortran/Makefile b/fortran/Makefile
index bbb15ab8..ab53e265 100644
--- a/fortran/Makefile
+++ b/fortran/Makefile
@@ -70,4 +70,4 @@ test_%:
 
 .PHONY: clean
 clean:
-	@rm -rf $(BUILD_DIR) test_runner
+	@rm -rf $(BUILD_DIR) test_runner problems.f90
diff --git a/fortran/problem_linker.sh b/fortran/problem_linker.sh
index 638ba24c..85723d68 100644
--- a/fortran/problem_linker.sh
+++ b/fortran/problem_linker.sh
@@ -17,7 +17,8 @@ for file in "$SRC_DIR"/p[0-9][0-9][0-9][0-9].f90; do
 done
 problem_ids_str=$(printf '%s_i4t, &\n' "${problem_ids[@]}")
 # Remove the last ', &\n' for proper formatting
-problem_ids_str=${problem_ids_str%, &$'\n'}
+length=${#problem_ids_str}
+problem_ids_str=${problem_ids_str:0:length - 3}
 
 # Start writing to the output file
 cat <<EOF1 > $OUTPUT_FILE
diff --git a/fortran/test.f90 b/fortran/test.f90
index deef9972..d56d49c5 100644
--- a/fortran/test.f90
+++ b/fortran/test.f90
@@ -17,7 +17,7 @@ subroutine process_problems()
         ! Loop through each problem
         do i = 1, size(problem_ids)
             print *, "Processing Problem ID: ", problem_ids(i)
-            if (is_slow(i)) then
+            if (is_slow(problem_ids(i))) then
                 print *, "  This problem will take more than 60 seconds."
             end if
             expected = get_answer(problem_ids(i))
@@ -68,7 +68,7 @@ subroutine process_problems()
                 tmp = tmp + count_max
             end if
             time_elapsed = real(tmp) / real(count_rate)
-            if (.NOT. is_slow(i) .AND. time_elapsed > 60.0) then
+            if (.NOT. is_slow(problem_ids(i)) .AND. time_elapsed > 60.0) then
                 print *, "  Error: problem ", problem_ids(i), " timed out!"
                 print *, "  Solution took    : ", time_elapsed, "s"
                 stop 2