diff --git a/basis/compiler/cfg/builder/builder-tests.factor b/basis/compiler/cfg/builder/builder-tests.factor
index 8da73a1e0e..db0dd65a83 100644
--- a/basis/compiler/cfg/builder/builder-tests.factor
+++ b/basis/compiler/cfg/builder/builder-tests.factor
@@ -192,14 +192,16 @@ IN: compiler.cfg.builder.tests
     [ [ ##unbox-alien? ] contains-insn? ] bi
 ] unit-test
 
-[ f t ] [
-    [ { byte-array fixnum } declare alien-cell 4 alien-float ]
-    [ [ ##box-alien? ] contains-insn? ]
-    [ [ ##box-float? ] contains-insn? ] bi
-] unit-test
+\ alien-float "intrinsic" word-prop [
+    [ f t ] [
+        [ { byte-array fixnum } declare alien-cell 4 alien-float ]
+        [ [ ##box-alien? ] contains-insn? ]
+        [ [ ##box-float? ] contains-insn? ] bi
+    ] unit-test
 
-[ f t ] [
-    [ { byte-array fixnum } declare alien-cell { simple-alien } declare 4 alien-float ]
-    [ [ ##box-alien? ] contains-insn? ]
-    [ [ ##box-float? ] contains-insn? ] bi
-] unit-test
\ No newline at end of file
+    [ f t ] [
+        [ { byte-array fixnum } declare alien-cell { simple-alien } declare 4 alien-float ]
+        [ [ ##box-alien? ] contains-insn? ]
+        [ [ ##box-float? ] contains-insn? ] bi
+    ] unit-test
+] when
\ No newline at end of file
diff --git a/basis/math/floats/env/env-tests.factor b/basis/math/floats/env/env-tests.factor
index 0c38d69ea9..c1d8913703 100644
--- a/basis/math/floats/env/env-tests.factor
+++ b/basis/math/floats/env/env-tests.factor
@@ -1,6 +1,7 @@
 USING: kernel math math.floats.env math.floats.env.private
 math.functions math.libm sequences tools.test locals
-compiler.units kernel.private fry compiler math.private words ;
+compiler.units kernel.private fry compiler math.private words
+system ;
 IN: math.floats.env.tests
 
 : set-default-fp-env ( -- )
@@ -29,7 +30,13 @@ set-default-fp-env
 [ t ] +fp-overflow+ [ 1.0e250 1.0e100 ] [ * ] test-fp-exception-compiled unit-test
 [ t ] +fp-underflow+ [ 1.0e-250 1.0e-100 ] [ * ] test-fp-exception-compiled unit-test
 [ t ] +fp-overflow+ [ 2.0 100,000.0 ] [ fpow ] test-fp-exception-compiled unit-test
-[ t ] +fp-underflow+ [ 2.0 -100,000.0 ] [ fpow ] test-fp-exception-compiled unit-test
+
+! No underflow on Linux with this test, just inexact. Reported as an Ubuntu bug:
+! https://bugs.launchpad.net/ubuntu/+source/glibc/+bug/429113
+os linux? cpu x86.64? and [
+    [ t ] +fp-underflow+ [ 2.0 -100,000.0 ] [ fpow ] test-fp-exception-compiled unit-test
+] unless
+
 [ t ] +fp-invalid-operation+ [ 0.0 0.0 ] [ /f ] test-fp-exception-compiled unit-test
 [ t ] +fp-invalid-operation+ [ -1.0 ] [ fsqrt ] test-fp-exception-compiled unit-test
 
@@ -106,19 +113,19 @@ set-default-fp-env
     append '[ _ _ with-fp-traps ] ;
 
 : test-traps-compiled ( traps inputs quot -- quot' )
-    swapd '[ _ [ _ _ with-fp-traps ] compile-call ] ;
+    swapd '[ @ [ _ _ with-fp-traps ] compile-call ] ;
 
-{ +fp-zero-divide+ }       [ 1.0 0.0 ] [ /f ] test-traps must-fail
-{ +fp-inexact+ }           [ 1.0 3.0 ] [ /f ] test-traps must-fail
+{ +fp-zero-divide+ } [ 1.0 0.0 ] [ /f ] test-traps must-fail
+{ +fp-inexact+ } [ 1.0 3.0 ] [ /f ] test-traps must-fail
 { +fp-invalid-operation+ } [ -1.0 ] [ fsqrt ] test-traps must-fail
-{ +fp-overflow+ }          [ 2.0 ] [ 100,000.0 ^ ] test-traps must-fail
-{ +fp-underflow+ }         [ 2.0 ] [ -100,000.0 ^ ] test-traps must-fail
+{ +fp-overflow+ } [ 2.0 ] [ 100,000.0 ^ ] test-traps must-fail
+{ +fp-underflow+ +fp-inexact+ } [ 2.0 ] [ -100,000.0 ^ ] test-traps must-fail
 
-{ +fp-zero-divide+ }       [ 1.0 0.0 ] [ /f ] test-traps-compiled must-fail
-{ +fp-inexact+ }           [ 1.0 3.0 ] [ /f ] test-traps-compiled must-fail
+{ +fp-zero-divide+ } [ 1.0 0.0 ] [ /f ] test-traps-compiled must-fail
+{ +fp-inexact+ } [ 1.0 3.0 ] [ /f ] test-traps-compiled must-fail
 { +fp-invalid-operation+ } [ -1.0 ] [ fsqrt ] test-traps-compiled must-fail
-{ +fp-overflow+ }          [ 2.0 ] [ 100,000.0 ^ ] test-traps-compiled must-fail
-{ +fp-underflow+ }         [ 2.0 ] [ -100,000.0 ^ ] test-traps-compiled must-fail
+{ +fp-overflow+ } [ 2.0 ] [ 100,000.0 ^ ] test-traps-compiled must-fail
+{ +fp-underflow+ +fp-inexact+ } [ 2.0 ] [ -100,000.0 ^ ] test-traps-compiled must-fail
 
 ! Ensure ordered comparisons raise traps
 :: test-comparison-quot ( word -- quot )
diff --git a/basis/math/functions/functions-tests.factor b/basis/math/functions/functions-tests.factor
index cde1c64f94..7a6da72005 100644
--- a/basis/math/functions/functions-tests.factor
+++ b/basis/math/functions/functions-tests.factor
@@ -33,9 +33,9 @@ IN: math.functions.tests
 [ 0.0 ] [ 1.0 log ] unit-test
 [ 1.0 ] [ e log ] unit-test
 
-[ t ] [ 1 exp e = ] unit-test
-[ t ] [ 1.0 exp e = ] unit-test
-[ 1.0 ] [ -1 exp e * ] unit-test
+[ t ] [ 1 exp e 1.e-10 ~ ] unit-test
+[ t ] [ 1.0 exp e 1.e-10 ~ ] unit-test
+[ t ] [ -1 exp e * 1.0 1.e-10 ~ ] unit-test
 
 [ 1.0 ] [ 0 cosh ] unit-test
 [ 1.0 ] [ 0.0 cosh ] unit-test
diff --git a/extra/benchmark/simd-1/simd-1.factor b/extra/benchmark/simd-1/simd-1.factor
index d5576b8cf5..4f57cca0bb 100644
--- a/extra/benchmark/simd-1/simd-1.factor
+++ b/extra/benchmark/simd-1/simd-1.factor
@@ -25,6 +25,6 @@ IN: benchmark.simd-1
     >fixnum make-points [ normalize-points ] [ max-points ] bi print-point ;
 
 : main ( -- )
-    5000000 simd-benchmark ;
+    10 [ 500000 simd-benchmark ] times ;
 
 MAIN: main
diff --git a/extra/benchmark/struct-arrays/struct-arrays.factor b/extra/benchmark/struct-arrays/struct-arrays.factor
index 799ef2d467..24c3ec965d 100644
--- a/extra/benchmark/struct-arrays/struct-arrays.factor
+++ b/extra/benchmark/struct-arrays/struct-arrays.factor
@@ -47,6 +47,6 @@ SPECIALIZED-ARRAY: point
 : struct-array-benchmark ( len -- )
     make-points [ normalize-points ] [ max-points ] bi print-point ;
 
-: main ( -- ) 5000000 struct-array-benchmark ;
+: main ( -- ) 10 [ 500000 struct-array-benchmark ] times ;
 
 MAIN: main