diff --git a/gentest.py b/gentest.py
index 118fae8..1fa2b0f 100644
--- a/gentest.py
+++ b/gentest.py
@@ -1,12 +1,18 @@
+# /// script
+# dependencies = ["numpy"]
+# ///
+
 import numpy as np
 
+
 def main():
     for endianness in "<>":
         for typ in "fiu":
             for size in "48":
-                dtype=endianness + typ + size
-                arr = np.zeros((2,3,4), dtype=dtype)
+                dtype = endianness + typ + size
+                arr = np.zeros((2, 3, 4), dtype=dtype)
                 np.save(f"test{dtype}.npy", arr)
 
-if __name__ == '__main__':
+
+if __name__ == "__main__":
     main()
diff --git a/npy.bqn b/npy.bqn
index 7763026..d3e997d 100644
--- a/npy.bqn
+++ b/npy.bqn
@@ -4,7 +4,11 @@ lf←@+10
 magicString←(@+147)∾"NUMPY"
 
 # Type conversions
-dtypes‿formats←⟨"<f8","<i4","<u4"⟩‿⟨64‿'f',32‿'i',32‿'u'⟩
+
+# CBQN does not support other widths than 1 for 'u'. However, signed
+# and unsigned integers seem to have the same behavior for numbers
+# below 2⋆31.
+dtypes‿formats←⟨"<f8","<i4","<u4"⟩‿⟨64‿'f',32‿'i',1‿'u'⟩
 DtypeToFormat←{(⊑dtypes⊐<𝕩)⊑formats}
 ArrayToBytes←{⟨DtypeToFormat 𝕨,8‿'c'⟩•bit._cast 𝕩}
 ArrayFromBytes←{⟨8‿'c',DtypeToFormat 𝕨⟩•bit._cast 𝕩}
diff --git a/tests.bqn b/tests.bqn
index d5c953c..5ccb29c 100644
--- a/tests.bqn
+++ b/tests.bqn
@@ -1,8 +1,8 @@
 ⟨SaveNpy,LoadNpy⟩←•Import"npy.bqn"
 
 floatArr←2‿3•rand.Range 0
-intArr←50-˜2‿3•rand.Range 100
-uintArr←2‿3•rand.Range 100
+intArr←(2⋆31)-˜2‿3•rand.Range 2⋆32
+uintArr←2‿3•rand.Range 2⋆31
 
 "test_float.npy"SaveNpy floatArr
 "test_int.npy"SaveNpy intArr