diff --git a/extra/benchmark/backtrack/backtrack.factor b/extra/benchmark/backtrack/backtrack.factor
index 856fd8e25d..befeaa856e 100644
--- a/extra/benchmark/backtrack/backtrack.factor
+++ b/extra/benchmark/backtrack/backtrack.factor
@@ -46,10 +46,8 @@ CONSTANT: words { 24-from-1 24-from-2 24-from-3 24-from-4 }
 
 : backtrack-benchmark ( -- )
     words [ reset-memoized ] each
-    find-impossible-24 pprint "/10000 quadruples can make 24." print
-    words [
-        dup pprint " tested " write "memoize" word-prop assoc-size pprint
-        " possibilities" print
-    ] each ;
+    find-impossible-24 6479 assert=
+    words [ "memoize" word-prop assoc-size ] map
+    { 1588 5137 4995 10000 } assert= ;
 
 MAIN: backtrack-benchmark
diff --git a/extra/benchmark/beust1/beust1.factor b/extra/benchmark/beust1/beust1.factor
index b18926b1a0..a28ff7c515 100644
--- a/extra/benchmark/beust1/beust1.factor
+++ b/extra/benchmark/beust1/beust1.factor
@@ -1,14 +1,12 @@
 ! Copyright (C) 2008 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: math.ranges math.parser math.vectors sets sequences
-kernel io ;
+USING: kernel math.ranges math.parser sets sequences ;
 IN: benchmark.beust1
 
 : count-numbers ( max -- n )
     1 [a,b] [ number>string all-unique? ] count ; inline
 
 : beust1-benchmark ( -- )
-    2000000 count-numbers
-    number>string " unique numbers." append print ;
+    2000000 count-numbers 229050 assert= ;
 
 MAIN: beust1-benchmark
diff --git a/extra/benchmark/beust2/beust2.factor b/extra/benchmark/beust2/beust2.factor
index 68f40ef399..2d37ab48f9 100644
--- a/extra/benchmark/beust2/beust2.factor
+++ b/extra/benchmark/beust2/beust2.factor
@@ -1,6 +1,6 @@
 ! Copyright (C) 2008 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: math math.ranges math.parser sequences kernel io locals ;
+USING: kernel locals math math.ranges math.parser sequences ;
 IN: benchmark.beust2
 
 ! http://crazybob.org/BeustSequence.java.html
@@ -34,6 +34,6 @@ IN: benchmark.beust2
 :: beust2-benchmark ( -- )
     0 :> i!
     5000000000 [ i 1 + i! ] count-numbers
-    i number>string " unique numbers." append print ;
+    i 7063290 assert= ;
 
 MAIN: beust2-benchmark
diff --git a/extra/benchmark/terrain-generation/terrain-generation.factor b/extra/benchmark/terrain-generation/terrain-generation.factor
index 41c1152cbd..e30579fead 100644
--- a/extra/benchmark/terrain-generation/terrain-generation.factor
+++ b/extra/benchmark/terrain-generation/terrain-generation.factor
@@ -1,11 +1,10 @@
 ! (c)Joe Groff bsd license
-USING: io kernel math.vectors.simd terrain.generation threads ;
+USING: accessors kernel math.vectors.simd terrain.generation ;
 FROM: alien.c-types => float ;
 IN: benchmark.terrain-generation
 
 : terrain-generation-benchmark ( -- )
-    "Generating terrain segment..." write flush yield
-    <terrain> float-4{ 0 0 0 1 } terrain-segment drop
-    "done" print ;
+    <terrain> float-4{ 0 0 0 1 } terrain-segment
+    dim>> { 512 512 } assert= ;
 
 MAIN: terrain-generation-benchmark