diff --git a/pkg/expressions/stdlib/funcs.go b/pkg/expressions/stdlib/funcs.go
index e07071f..a22c8f3 100644
--- a/pkg/expressions/stdlib/funcs.go
+++ b/pkg/expressions/stdlib/funcs.go
@@ -20,8 +20,18 @@ var StandardFunctions = map[string]KeyBuilderFunction{
 	"sumi":  arithmaticHelperi(func(a, b int) int { return a + b }),
 	"subi":  arithmaticHelperi(func(a, b int) int { return a - b }),
 	"multi": arithmaticHelperi(func(a, b int) int { return a * b }),
-	"divi":  arithmaticHelperi(func(a, b int) int { return a / b }),
-	"modi":  arithmaticHelperi(func(a, b int) int { return a % b }),
+	"divi": arithmaticHelperi(func(a, b int) int {
+		if b == 0 {
+			return math.MaxInt
+		}
+		return a / b
+	}),
+	"modi": arithmaticHelperi(func(a, b int) int {
+		if b == 0 {
+			return 0
+		}
+		return a % b
+	}),
 	"maxi": arithmaticHelperi(func(a, b int) int {
 		if a > b {
 			return a
diff --git a/pkg/expressions/stdlib/funcs_test.go b/pkg/expressions/stdlib/funcs_test.go
new file mode 100644
index 0000000..f5fcfed
--- /dev/null
+++ b/pkg/expressions/stdlib/funcs_test.go
@@ -0,0 +1,82 @@
+package stdlib
+
+import (
+	"rare/pkg/expressions"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// Try to input-search for panics or other errors
+// Doesn't check for correctness, just tries to break things
+func TestAllFuncsNoPanic(t *testing.T) {
+	// tests numerous combinations to assure code paths work and never panic
+	if testing.Short() {
+		t.SkipNow()
+	}
+
+	var argSets = [][]string{
+		{"0", "5", "10", "20", "30", "40", "50", "60", "70", "100"},
+		{"50", "40", "30", "20", "10", "0"},
+		{"a", "b", "c", "d", "e", "f", "g", "h", "i", "j"},
+		{"", "", "", "", "", "", "", "", "", ""},
+	}
+
+	for name, fn := range StandardFunctions {
+		t.Run(name, func(t *testing.T) {
+
+			// run function with each argset and subset
+			for _, argSet := range argSets {
+
+				literalSet := make([]expressions.KeyBuilderStage, 0, len(argSet))
+				contextSet := make([]expressions.KeyBuilderStage, 0, len(argSet))
+
+				for i, arg := range argSet {
+					// Compile and execute using a set of literals
+					literalSet = append(literalSet, literal(arg))
+
+					assert.NotPanics(t, func() {
+						compiledFunc, err := fn(literalSet)
+
+						// if compiled, try to invoke
+						if err == nil {
+							assert.NotNil(t, compiledFunc)
+						}
+
+						if compiledFunc != nil {
+							// even if err isn't nil, if it exists
+							// it should also be runnable
+							compiledFunc(mockContext())
+						}
+					})
+
+					// try the same thing, but with contextual inputs
+					argIdx := i
+					contextSet = append(contextSet, func(kbc expressions.KeyBuilderContext) string { return kbc.GetMatch(argIdx) })
+					ctx := &expressions.KeyBuilderContextArray{
+						Elements: argSet[:i+1],
+					}
+
+					assert.NotPanics(t, func() {
+						compiledFunc, err := fn(contextSet)
+
+						// if compiled, try to invoke
+						if err == nil {
+							assert.NotNil(t, compiledFunc)
+						}
+
+						if compiledFunc != nil {
+							// even if err isn't nil, if it exists
+							// it should also be runnable
+							compiledFunc(ctx)
+						}
+					})
+
+				}
+			}
+
+		})
+
+	}
+
+}