diff --git a/src/bootstrap.zig b/src/bootstrap.zig
index a1b3eac..5296927 100644
--- a/src/bootstrap.zig
+++ b/src/bootstrap.zig
@@ -107,6 +107,14 @@ fn is_decimal_ch(ch: u8) bool {
     return ch >= '0' and ch <= '9';
 }
 
+fn is_octal_ch(ch: u8) bool {
+    return ch >= '0' and ch <= '7';
+}
+
+fn is_binary_ch(ch: u8) bool {
+    return ch == '0' or ch == '1';
+}
+
 fn is_identifier_ch(ch: u8) bool {
     return is_identifier_start_ch(ch) or is_decimal_ch(ch);
 }
@@ -1173,6 +1181,36 @@ pub const Module = struct {
         return value;
     }
 
+    fn parse_octal(noalias module: *Module) u64 {
+        var value: u64 = 0;
+        while (true) {
+            const ch = module.content[module.offset];
+            if (!is_octal_ch(ch)) {
+                break;
+            }
+
+            module.offset += 1;
+            value = lib.parse.accumulate_octal(value, ch);
+        }
+
+        return value;
+    }
+
+    fn parse_binary(noalias module: *Module) u64 {
+        var value: u64 = 0;
+        while (true) {
+            const ch = module.content[module.offset];
+            if (!is_binary_ch(ch)) {
+                break;
+            }
+
+            module.offset += 1;
+            value = lib.parse.accumulate_binary(value, ch);
+        }
+
+        return value;
+    }
+
     const AttributeBuildOptions = struct {
         return_type_abi: Abi.Information,
         abi_argument_types: []const *Type,
@@ -2023,16 +2061,32 @@ pub const Module = struct {
                     'x' => .hexadecimal,
                     'o' => .octal,
                     'b' => .binary,
+                    'd' => .decimal,
                     else => .decimal,
                 };
                 const value: u64 = switch (token_integer_kind) {
-                    .binary => @trap(),
-                    .octal => @trap(),
+                    .binary => b: {
+                        module.offset += 2;
+                        const v = module.parse_binary();
+                        break :b v;
+                    },
+                    .octal => b: {
+                        module.offset += 2;
+                        const v = module.parse_octal();
+                        break :b v;
+                    },
                     .decimal => switch (next_ch) {
                         0...9 => module.report_error(),
-                        else => b: {
-                            module.offset += 1;
-                            break :b 0;
+                        else => switch (next_ch) {
+                            'd' => b: {
+                                module.offset += 2;
+                                const v = module.parse_decimal();
+                                break :b v;
+                            },
+                            else => b: {
+                                module.offset += 1;
+                                break :b 0;
+                            },
                         },
                     },
                     .hexadecimal => b: {
@@ -4087,13 +4141,17 @@ pub const Module = struct {
                             module.offset += 1;
                             break :b module.parse_hexadecimal();
                         },
-                        'o' => {
-                            // TODO: parse octal
-                            module.report_error();
+                        'd' => b: {
+                            module.offset += 1;
+                            break :b module.parse_decimal();
                         },
-                        'b' => {
-                            // TODO: parse binary
-                            module.report_error();
+                        'o' => b: {
+                            module.offset += 1;
+                            break :b module.parse_octal();
+                        },
+                        'b' => b: {
+                            module.offset += 1;
+                            break :b module.parse_binary();
                         },
                         '0'...'9' => {
                             module.report_error();
diff --git a/src/compiler.bbb b/src/compiler.bbb
index 4882790..52f2bac 100644
--- a/src/compiler.bbb
+++ b/src/compiler.bbb
@@ -174,6 +174,7 @@ os_commit = fn (address: u64, size: u64, protection: OS_ProtectionFlags) void
 
 os_make_directory = fn (path: &u8) void
 {
+    >result = mkdir(path, 0o755);
 }
 
 Arena = struct
diff --git a/src/lib.zig b/src/lib.zig
index 0d7115e..8957823 100644
--- a/src/lib.zig
+++ b/src/lib.zig
@@ -2865,6 +2865,14 @@ pub const parse = struct {
     pub fn accumulate_decimal(accumulator: u64, ch: u8) u64 {
         return (accumulator * 10) + (ch - '0');
     }
+
+    pub fn accumulate_octal(accumulator: u64, ch: u8) u64 {
+        return (accumulator * 8) + (ch - '0');
+    }
+
+    pub fn accumulate_binary(accumulator: u64, ch: u8) u64 {
+        return (accumulator * 2) + (ch - '0');
+    }
 };
 
 test "parse integer decimal" {
diff --git a/src/main.zig b/src/main.zig
index 1480e53..4a25e2f 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -320,4 +320,6 @@ const names = &[_][]const u8{
     "pointer_decay",
     "enum_name",
     "slice_of_slices",
+    "type_alias",
+    "integer_formats",
 };
diff --git a/tests/integer_formats.bbb b/tests/integer_formats.bbb
new file mode 100644
index 0000000..88c6bc1
--- /dev/null
+++ b/tests/integer_formats.bbb
@@ -0,0 +1,7 @@
+[export] main = fn [cc(c)] () s32
+{
+    >a: s32 = 0o10;
+    >b: s32 = 0b1000;
+    >c: s32 = 0d0;
+    return a - b + c;
+}