diff --git a/README.md b/README.md
index d1fef1a..abc250a 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,17 @@ files defined in its respective module. This allows testing internal functions.
 To run the tests, simply run `make test`. If you wish to only run a specific
 test binary, you can find them in `build/test`.
 
+The name of tests in the `TEST_LIST` variable should be prefixed with the
+module they're testing. This makes it much easier to distinguish the output of
+tests in the CLI. For example:
+
+```c
+TEST_LIST = {
+    {"cron illegal parts", test_illegal_parts},
+    {NULL, NULL}
+};
+```
+
 ### `compile_commands.json`
 
 Clangd requires a `compile_commands.json` to function properly. You can
diff --git a/src/cron/vieter_cron_parse.c b/src/cron/vieter_cron_parse.c
index a82d1c3..b42e1a9 100644
--- a/src/cron/vieter_cron_parse.c
+++ b/src/cron/vieter_cron_parse.c
@@ -1,4 +1,4 @@
-#include "vieter_cron.h"
+#include "vieter_cron_parse.h"
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/src/cron/vieter_cron_parse.h b/src/cron/vieter_cron_parse.h
new file mode 100644
index 0000000..21ccf81
--- /dev/null
+++ b/src/cron/vieter_cron_parse.h
@@ -0,0 +1,11 @@
+#ifndef VIETER_CRON_PARSE
+#define VIETER_CRON_PARSE
+
+#include "vieter_cron.h"
+
+vieter_cron_parse_error vieter_cron_expr_parse_range(uint64_t *out, char *s,
+                                                     uint8_t min, uint8_t max);
+
+vieter_cron_parse_error vieter_cron_expr_parse_part(uint64_t *out, char *s,
+                                                    uint8_t min, uint8_t max);
+#endif
diff --git a/test/cron/test_parse.c b/test/cron/test_parse.c
index 030c720..6417c40 100644
--- a/test/cron/test_parse.c
+++ b/test/cron/test_parse.c
@@ -1,7 +1,7 @@
 #include "acutest.h"
 #include "vieter_cron.h"
 
-void test_not_allowed() {
+void test_illegal_expressions() {
     char *expressions[] = {
         "4 *-7",
         "4 *-7/4",
@@ -33,6 +33,6 @@ void test_not_allowed() {
 }
 
 TEST_LIST = {
-    {"not_allowed", test_not_allowed},
+    {"cron illegal expressions", test_illegal_expressions},
     {NULL, NULL}
 };
diff --git a/test/cron/test_parse_part.c b/test/cron/test_parse_part.c
new file mode 100644
index 0000000..5c9c10e
--- /dev/null
+++ b/test/cron/test_parse_part.c
@@ -0,0 +1,43 @@
+#include "acutest.h"
+#include "vieter_cron_parse.h"
+
+struct parse_test {
+    char *part;
+    uint8_t min;
+    uint8_t max;
+};
+
+void test_illegal_parts() {
+    struct parse_test parts[] = {
+        { "*-7", 0, 23 },
+        { "*-7/4", 0, 23 },
+        { "7/*", 0, 23 },
+        { "/5", 0, 23 },
+        { "4~6", 0, 23 },
+        { "5/2-5", 0, 23 },
+        { "1/2/3", 0, 23 },
+        { "*5", 0, 59 },
+        { "x", 0, 59 },
+        { NULL, 0, 0 }
+    };
+
+    int i = 0;
+    uint64_t out;
+    char *s;
+
+    while (parts[i].part != NULL) {
+        // Function modifies string in-place
+        s = strdup(parts[i].part);
+
+        TEST_CHECK_(vieter_cron_expr_parse_part(&out, s, parts[i].min, parts[i].max) != vieter_cron_parse_ok, "%s (%i - %i)", parts[i].part, parts[i].min, parts[i].max);
+
+        free(s);
+
+        i++;
+    }
+}
+
+TEST_LIST = {
+    {"cron illegal parts", test_illegal_parts},
+    {NULL, NULL}
+};
diff --git a/test/heap/test_heap.c b/test/heap/test_heap.c
index f77b0dc..31ea354 100644
--- a/test/heap/test_heap.c
+++ b/test/heap/test_heap.c
@@ -178,10 +178,10 @@ void test_pop_random() {
 }
 
 TEST_LIST = {
-    {"init", test_init},
-    {"insert", test_insert},
-    {"insert random", test_insert_random},
-    {"pop", test_pop},
-    {"pop random", test_pop_random},
+    {"heap init", test_init},
+    {"heap insert", test_insert},
+    {"heap insert random", test_insert_random},
+    {"heap pop", test_pop},
+    {"heap pop random", test_pop_random},
     {NULL, NULL}
 };
diff --git a/test/heap/test_merge.c b/test/heap/test_merge.c
index 10053f2..f0861fe 100644
--- a/test/heap/test_merge.c
+++ b/test/heap/test_merge.c
@@ -23,6 +23,6 @@ void test_merge_same_order() {
 }
 
 TEST_LIST = {
-    {"merge same order", test_merge_same_order},
+    {"heap merge same order", test_merge_same_order},
     {NULL, NULL}
 };
diff --git a/test/tree/test_binary_tree.c b/test/tree/test_tree.c
similarity index 93%
rename from test/tree/test_binary_tree.c
rename to test/tree/test_tree.c
index aa7fc0f..d0ea661 100644
--- a/test/tree/test_binary_tree.c
+++ b/test/tree/test_tree.c
@@ -51,8 +51,8 @@ void test_remove() {
 }
 
 TEST_LIST = {
-    {"test_init", test_init},
-    {"test_insert", test_insert},
-    {"test_remove", test_remove},
+    {"tree init", test_init},
+    {"tree insert", test_insert},
+    {"tree remove", test_remove},
     {NULL, NULL}
 };