diff --git a/src/distributions/exponential.rs b/src/distributions/exponential.rs
index bbdebacab71..b246c3502b1 100644
--- a/src/distributions/exponential.rs
+++ b/src/distributions/exponential.rs
@@ -107,7 +107,6 @@ mod test {
         let mut rng = ::test::rng(221);
         for _ in 0..1000 {
             assert!(exp.sample(&mut rng) >= 0.0);
-            assert!(exp.sample(&mut rng) >= 0.0);
         }
     }
     #[test]
diff --git a/src/distributions/gamma.rs b/src/distributions/gamma.rs
index f9dbbb96139..361e12ed6a2 100644
--- a/src/distributions/gamma.rs
+++ b/src/distributions/gamma.rs
@@ -318,7 +318,6 @@ mod test {
         let mut rng = ::test::rng(201);
         for _ in 0..1000 {
             chi.sample(&mut rng);
-            chi.sample(&mut rng);
         }
     }
     #[test]
@@ -327,7 +326,6 @@ mod test {
         let mut rng = ::test::rng(202);
         for _ in 0..1000 {
             chi.sample(&mut rng);
-            chi.sample(&mut rng);
         }
     }
     #[test]
@@ -336,7 +334,6 @@ mod test {
         let mut rng = ::test::rng(203);
         for _ in 0..1000 {
             chi.sample(&mut rng);
-            chi.sample(&mut rng);
         }
     }
     #[test]
@@ -351,7 +348,6 @@ mod test {
         let mut rng = ::test::rng(204);
         for _ in 0..1000 {
             f.sample(&mut rng);
-            f.sample(&mut rng);
         }
     }
 
@@ -361,7 +357,6 @@ mod test {
         let mut rng = ::test::rng(205);
         for _ in 0..1000 {
             t.sample(&mut rng);
-            t.sample(&mut rng);
         }
     }
 }
diff --git a/src/distributions/integer.rs b/src/distributions/integer.rs
index 8bac2bbfdfd..6b3a903bedf 100644
--- a/src/distributions/integer.rs
+++ b/src/distributions/integer.rs
@@ -108,3 +108,31 @@ impl Distribution<u128> for Uniform {
         ((rng.next_u64() as u128) << 64) | (rng.next_u64() as u128)
     }
 }
+
+
+#[cfg(test)]
+mod tests {
+    use Rng;
+    use distributions::{Uniform};
+    
+    #[test]
+    fn test_integers() {
+        let mut rng = ::test::rng(806);
+        
+        rng.sample::<isize, _>(Uniform);
+        rng.sample::<i8, _>(Uniform);
+        rng.sample::<i16, _>(Uniform);
+        rng.sample::<i32, _>(Uniform);
+        rng.sample::<i64, _>(Uniform);
+        #[cfg(feature = "i128_support")]
+        rng.sample::<i128, _>(Uniform);
+        
+        rng.sample::<usize, _>(Uniform);
+        rng.sample::<u8, _>(Uniform);
+        rng.sample::<u16, _>(Uniform);
+        rng.sample::<u32, _>(Uniform);
+        rng.sample::<u64, _>(Uniform);
+        #[cfg(feature = "i128_support")]
+        rng.sample::<u128, _>(Uniform);
+    }
+}
diff --git a/src/distributions/normal.rs b/src/distributions/normal.rs
index bd3ba24d463..089cb9046d5 100644
--- a/src/distributions/normal.rs
+++ b/src/distributions/normal.rs
@@ -167,7 +167,6 @@ mod tests {
         let mut rng = ::test::rng(210);
         for _ in 0..1000 {
             norm.sample(&mut rng);
-            norm.sample(&mut rng);
         }
     }
     #[test]
@@ -183,7 +182,6 @@ mod tests {
         let mut rng = ::test::rng(211);
         for _ in 0..1000 {
             lnorm.sample(&mut rng);
-            lnorm.sample(&mut rng);
         }
     }
     #[test]
diff --git a/src/distributions/other.rs b/src/distributions/other.rs
index 75cf2f20465..873043addac 100644
--- a/src/distributions/other.rs
+++ b/src/distributions/other.rs
@@ -113,3 +113,17 @@ impl<T> Distribution<Option<T>> for Uniform where Uniform: Distribution<T> {
         }
     }
 }
+
+
+#[cfg(test)]
+mod tests {
+    use {Rng, RngCore, Uniform};
+    
+    #[test]
+    fn test_misc() {
+        let mut rng: &mut RngCore = &mut ::test::rng(820);
+        
+        rng.sample::<char, _>(Uniform);
+        rng.sample::<bool, _>(Uniform);
+    }
+}