diff --git a/src/ticks.jl b/src/ticks.jl
index 7241e63..8ddb977 100644
--- a/src/ticks.jl
+++ b/src/ticks.jl
@@ -30,10 +30,12 @@ function bounding_order_of_magnitude(xspan::T, base::T) where {T}
 end
 
 function postdecimal_digits(x::T) where {T}
-    for i in floor(Int, log10(floatmin(T))):ceil(Int, log10(floatmax(T)))
+    isinteger(x) && return 0
+    max = ceil(Int, log10(floatmax(T)))
+    for i in 0:max
         x == floor(x; digits = i) && return i
     end
-    return 0
+    return max
 end
 
 fallback_ticks(x_min::T, x_max::T, k_min, k_max) where {T} = (
diff --git a/test/runtests.jl b/test/runtests.jl
index 3e47fbe..3144783 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -270,3 +270,22 @@ end
     @test stats.bytes < 1_000  # ~ 848 (on 1.6)
     @test stats.time < 1e-3  # ~ 0.45ms (on 1.6)
 end
+
+# ----------------------
+# digits
+
+@testset "Decimal digits" begin
+    @test PlotUtils.postdecimal_digits(1.245) == 3
+    @test PlotUtils.postdecimal_digits(11.234) == 3
+    @test PlotUtils.postdecimal_digits(1 / 3) == 16
+    @test PlotUtils.postdecimal_digits(1.234e-2) == 5
+    @test PlotUtils.postdecimal_digits(1.234f-3) == 6
+    @test PlotUtils.postdecimal_digits(0.284882f0) == 6
+    @test PlotUtils.postdecimal_digits(0.5517515f0) == 7
+    @test PlotUtils.postdecimal_digits(0.1578114989219891) == 16
+    @test PlotUtils.postdecimal_digits(0.35722002265961517) == 17
+    @test PlotUtils.postdecimal_digits(0.046297550780936114) == 18
+    @test PlotUtils.postdecimal_digits(2.5e-22) == 25
+    @test PlotUtils.postdecimal_digits(floatmin(Float64)) == 309
+    @test PlotUtils.postdecimal_digits(floatmin(Float32)) == 39
+end